497 1 a18-36514_1497.htm 497

THE
ALGER FUNDS

Available for investment by Institutional Investors

Prospectus March 1, 2018

	Class		Ticker Symbol
Alger Capital Appreciation Fund		Z	ACAZX
Alger Mid Cap Growth Fund		Z	AMCZX
Alger SMid Cap Focus Fund		I Y Z	ASIMX ASYMX ASMZX
Alger Small Cap Growth Fund		Z	ASCZX
Alger Small Cap Focus Fund		I Y Z	AOFIX AOFYX AGOZX
Alger Health Sciences Fund		Z	AHSZX
Alger Growth & Income Fund		Z	AGIZX

As with all mutual funds, the Securities and Exchange Commission has not determined if the information in this Prospectus is accurate or complete, nor has it approved or disapproved these securities. It is a criminal offense to represent otherwise.

Table of Contents

THE ALGER FUNDS
	1	Summary Sections
	1	Alger Capital Appreciation Fund
	7	Alger Mid Cap Growth Fund
	13	Alger SMid Cap Focus Fund
	34	Alger Small Cap Growth Fund
	40	Alger Small Cap Focus Fund
	58	Alger Health Sciences Fund
	64	Alger Growth & Income Fund
	70	Investment Objectives, Principal Investment Strategies and Related Risks
	71	Additional Information About the Funds' Investment Strategies and Investments
	78	Management and Organization
	81	Hypothetical Investment and Expense Information
	84	Financial Highlights
	A-1	Shareholder Information
	A-1	Distributor
	A-1	Transfer Agent
	A-1	Net Asset Value
	A-2	Dividends and Distributions and Tax Consequences
	A-3	Classes of Fund Shares
	A-3	Purchasing and Redeeming Fund Shares
	A-6	Exchanges
	A-6	Other Purchase and Exchange Limitations
	A-6	Limitations on Excessive Trading
	A-7	Disclosure of Portfolio Holdings
	A-8	Other Information
	A-11	For Fund Information

Summary Sections

Alger Capital Appreciation Fund

Investment Objective

Alger Capital Appreciation Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Capital Appreciation Fund
Class	Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees*		.77	%*
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.11	%
Total Annual Fund Operating Expenses		.88	%

* The Fund and Fred Alger Management, Inc. have adopted fee breakpoints for Alger Capital Appreciation Fund. The management fee for assets up to $2 billion is .81%. The management fee for assets between $2 billion and $3 billion is .65%, for assets between $3 billion and $4 billion is .60%, for assets between $4 billion and $5 billion is .55%, and for assets in excess of $5 billion is .45%. The actual rate paid as a percentage of average daily net assets for the period ended October 31, 2017, was .77%.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	90			$	281			$	488			$	1,084

Prospectus 1/95

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 72.99% of the average value of its portfolio.

Principal Investment Strategy

Fred Alger Management, Inc. believes companies undergoing Positive Dynamic Change offer the best investment opportunities. Positive Dynamic Change refers to companies realizing High Unit Volume Growth or companies undergoing Positive Lifecycle Change. High Unit Volume Growth companies are traditional growth companies experiencing, for example, significantly growing demand or market dominance. Positive Lifecycle Change companies are, for example, companies benefitting from regulatory change, a new product introduction or management change.

Under normal market circumstances, the Fund invests at least 85% of its net assets, plus any borrowings for investment purposes, in equity securities of companies of any market capitalization that Fred Alger Management, Inc. believes demonstrate promising growth potential. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges.

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

The Fund can leverage, that is, borrow money to buy additional securities. By borrowing money, the Fund has the potential to increase its returns if the increase in the value of the securities purchased exceeds the cost of borrowing, including interest paid on the money borrowed. However, leverage also has the potential to magnify any decrease in the value of the purchased securities.

The Fund may invest a significant portion of its assets in securities of companies conducting business within a single sector, including the information technology, consumer discretionary, and health care sectors.

Principal Risks

An investment in the Fund involves risks. The Fund's share price may go down, which means you could lose money. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Market Risk – Your investment in Fund shares represents an indirect investment in the securities owned by the Fund. The value of these securities, like other investments, may move up or down, sometimes rapidly and unpredictably. Your Fund shares at any point in time may be worth less than what you invested, even after taking into account the reinvestment of Fund dividends and distributions.

Equity Securities Risk – As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. The Fund's price per share will fluctuate due to changes in the market prices of its investments. Also, the Fund's investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds.

Growth Stocks Risk – Prices of growth stocks tend to be higher in relation to their companies' earnings and may be more sensitive to market, political and economic developments than other stocks, making their prices more volatile. An investment in the Fund may be better suited to investors who seek long-term capital growth and can tolerate fluctuations in their investment's value.

Sector Risk – The Fund may have a significant portion of its assets invested in securities of companies conducting business within a single sector. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Technology Companies Risk – The Fund may have a significant portion of its assets invested in securities of technology companies. Many technology companies have limited operating histories and prices of these companies' securities have historically been more volatile than other securities, especially over the short term. Technology companies may also face increased competition, government regulation, and risk of obsolescence due to progress in technological developments.

Smaller Cap Securities Risk – Investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Prospectus 3/95

Leverage Risk – The cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus, the Fund's net asset value can decrease more quickly than if the Fund had not borrowed.

Performance

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2012 16.75%

Worst Quarter:
Q3 2011 -15.41%

Prospectus 4/95

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class Z (Inception 12/29/10)
Return Before Taxes		31.69	%		16.75	%		14.25	%
Return After Taxes on Distributions		29.68	%		14.55	%		12.64	%
Return After Taxes on Distributions and Sale of Fund Shares		19.46	%		12.93	%		11.22	%
Russell 1000 Growth Index (reflects no deductions for fees, expenses or taxes)		30.21	%		17.33	%		14.76	%

In the foregoing table, after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. The after-tax returns shown may not be relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. A "Return After Taxes on Distributions and Sale of Fund Shares" may sometimes be higher than the other two return figures; this happens when there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Ankur Crawford, Ph.D. Senior Vice President and Portfolio Manager Since June 2015
				Patrick Kelly, CFA Executive Vice President, Head of Alger Capital Appreciation and Spectra Strategies and Portfolio Manager Since September 2004

Shareholder Information

Purchasing and Redeeming Fund Shares

The Fund's Class Z Shares are generally subject to a minimum initial investment of $500,000, which may be waived for group employer-sponsored 401(k) plans, 457 plans, employer sponsored 403(b) plans, profit-sharing and money purchase pension plans, defined benefit plans, retiree health benefit plans and non-qualified deferred compensation plans. The waiver is available only for retirement plans that hold omnibus positions, or for aggregate plan participant positions, for each Fund made available for the plan. The waiver is generally not available to non-retirement accounts, traditional and Roth Individual Retirement Accounts, Coverdell Education

Prospectus 5/95

Savings Accounts, SEPs, SARSEPs, SIMPLE IRAs, individual 401(k) plans or individual 403(b) plans.

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary's website for more information.

Prospectus 6/95

Alger Mid Cap Growth Fund

Investment Objective

Alger Mid Cap Growth Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Class Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.76	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.31	%
Total Annual Fund Operating Expenses		1.07	%
Fee Waiver and/or Expense Reimbursement*		(.02	)%*
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		1.05	%

* Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019, to the extent necessary to limit the annual operating expenses of the Fund's Class Z Shares to 1.05% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	107			$	338			$	588			$	1.304

Prospectus 7/95

Portfolio Turnover

Principal Investment Strategy

The Fund focuses on mid-sized companies that Fred Alger Management, Inc. believes demonstrate promising growth potential. Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities of companies that, at the time of purchase of the securities, have total market capitalization within the range of companies included in the Russell Midcap Growth Index or the S&P MidCap 400 Index, as reported by the indexes as of the most recent quarter-end. Both indexes are designed to track the performance of medium-capitalization stocks. At December 31, 2017, the market capitalization of the companies in these indexes ranged from $626.1 million to $36.7 billion. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges.

The Fund may invest a significant portion of its assets in securities of companies conducting business within a single sector, including the information technology, healthcare, consumer discretionary, and industrials sectors.

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive. As a result, the Fund may engage in active trading of portfolio securities.

The Fund can invest in foreign securities.

Principal Risks

Prospectus 8/95

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Mid Cap Securities Risk – There may be greater risk in investing in medium-capitalization companies rather than larger, more established companies due to such factors as inexperienced management and limited product lines or financial resources. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Sector Risk — The Fund may have a significant portion of its assets invested in securities of companies conducting business within a single sector. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Prospectus 9/95

companies may also be significantly affected by intense competition, aggressive pricing, government regulation, technological innovations, product obsolescence, patent considerations, product compatibility and consumer preferences.

Portfolio Turnover (Active Trading) Risk – Because the Fund may engage in active trading of portfolio securities, it may incur increased transaction costs and brokerage commissions, both of which can lower the actual return on an investment. Active trading may also increase short-term gains and losses, which may affect the taxes a shareholder has to pay.

Foreign Securities Risk – The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign companies. Special risks associated with investments in foreign companies include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards.

Performance

Prospectus 10/95

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2017 10.57%

Worst Quarter:
Q1 2016 -4.45%

Average Annual Total Return as of December 31, 2017

	1 Year			Since Inception
Class Z (Inception 5/28/15)
Return Before Taxes		29.98	%		6.85	%
Return After Taxes on Distributions		29.72	%		6.77	%
Return After Taxes on Distributions and Sale of Fund Shares		17.17	%		5.28	%
Russell Midcap Growth Index (reflects no deductions for fees, expenses or taxes)		25.27	%		9.32	%

In the foregoing table, after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. The after-tax returns shown may not be relevant to investors who hold their Fund Shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. A "Return After Taxes on Distributions and Sale of Fund Shares" may sometimes be higher than the other two return figures; this happens when there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.

Prospectus 11/95

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Dan C. Chung, CFA Chief Executive Officer, Chief Investment Officer and Portfolio Manager Since January 2018
				Teresa McRoberts Senior Vice President, Senior Analyst and Portfolio Manager Since February 2015
				Christopher R. Walsh, CFA Senior Vice President, Senior Analyst and Portfolio Manager Since February 2013

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 12/95

Alger SMid Cap Focus Fund

Investment Objective

Alger SMid Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger SMid Cap Focus Fund
Class	I
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.81	%
Distribution and/or Shareholder Servicing (12b-1) Fees		.25	%
Other Expenses		.29	%
Total Annual Fund Operating Expenses		1.35	%

Example

				1 Year				3 Years				5 Years				10 Years
Class I				$	137			$	428			$	739			$	1,624

Portfolio Turnover

Prospectus 13/95

Principal Investment Strategy

Weatherbie Capital, LLC ("Weatherbie"), an affiliate of Fred Alger Management, Inc. and the Fund's sub-adviser, invests in smaller cap U. S. growth companies that Weatherbie believes have enduring earnings, reasonable valuations and a distinct competitive advantage. Weatherbie invests in Foundation growth stocks and Opportunity growth stocks. Foundation growth stocks are companies led by experienced management teams, with innovative business models and the potential for high sales and earnings growth. Opportunity growth stocks are companies whose earnings may be temporarily depressed, but change is underway that Weatherbie believes can reaccelerate earnings.

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of smallcap and midcap companies. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges. Smallcap or midcap companies are companies that, at the time of purchase, have total market capitalization within the range of companies included in the Russell 2500 Growth Index or the Russell Midcap Growth Index, respectively, as reported by the indexes as of the most recent quarter-end. At December 31, 2017, the market capitalization of the companies in these indexes ranged from $22.5 million to $36.7 billion.

As a focus fund, the Fund intends to invest a substantial portion of its assets in a smaller number of issuers, and may focus its holdings in fewer business sectors or industries. Generally the Fund will own approximately 50 holdings. Fund holdings may occasionally exceed this number for a variety of reasons.

The Fund can invest in foreign securities.

Prospectus 14/95

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Small and Mid Cap Securities Risk – There may be greater risk in investing in companies with small or medium market capitalizations rather than larger, more established issuers owing to such factors as more limited product lines or financial resources or lack of management depth. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

Less Diversified Portfolio Risk – The Fund may have a more concentrated portfolio than other funds, so it may be more vulnerable to changes in the market value of a single issuer and may be more susceptible to risks associated with a single economic, political or regulatory occurrence than a fund that has a more diversified portfolio. The Fund may have substantial holdings within a particular sector, and companies in similar industries may be similarly affected by particular economic or market events.

Prospectus 15/95

Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Leverage Risk – The cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus the Fund's net asset value could decrease more quickly than if it had not borrowed.

Performance

The following bar chart and the table beneath it provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the indicated periods compare with those of an appropriate benchmark of market performance. Performance prior to August 6, 2007, commencement of the Class I Share's operations, is that of the Fund's Class A Shares. Prior to August 30, 2017, the Fund followed different investment strategies under the name "Alger SMid Cap Growth Fund" and prior to March 1, 2017 was managed by different portfolio managers. Accordingly, performance prior to those dates does not reflect the Fund's current investment strategies and investment personnel. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Prospectus 16/95

Annual Total Return For Class I Shares* as of December 31 (%)

Best Quarter:
Q2 2009 18.02%

Worst Quarter:
Q4 2008 -28.32%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			10 Years			Since 5/8/02
Class I (Inception 8/6/07)
Return Before Taxes		37.90	%		14.00	%		6.82	%		9.39	%
Return After Taxes on Distributions		31.67	%		8.84	%		4.31	%		7.51	%
Return After Taxes on Distributions and Sale of Fund Shares		21.92	%		9.77	%		4.81	%		7.41	%
Russell 2500 Growth Index (reflects no deductions for fees, expenses or taxes)		24.46	%		15.47	%		9.62	%		9.70	%

* Performance of the Fund's Class I Shares prior to August 6, 2007 reflects the performance of the Fund's Class A Shares, as adjusted with currently applicable sales charges and operating expenses, which differ from historical charges and expenses.

Prospectus 17/95

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.

Sub-Adviser:

Weatherbie Capital, LLC*				H. George Dai, Ph.D. Senior Managing Director and Co-Chief Investment Officer of Weatherbie Since March 2017
				Joshua D. Bennett, CFA Senior Managing Director, Director of Research of Weatherbie Since March 2017
				Matthew A. Weatherbie, CFA President, Chief Executive Officer and Co-Chief Investment Officer of Weatherbie Since March 2017

* Weatherbie Capital, LLC, an affiliate of Fred Alger Management, Inc., sub-advises the Fund subject to Fred Alger Management, Inc.'s supervision and approval.

Shareholder Information

Purchasing and Redeeming Fund Shares

The Fund's Class I Shares are not subject to a minimum initial investment. Class I Shares are an investment vehicle principally for institutional investors such as registered investment advisers, banks, trust companies, and other financial institutions, for investments in employee benefit plans, or for advisory platform investors who pay a separate fee to such institution for the right to invest.

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Prospectus 18/95

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 19/95

Alger SMid Cap Focus Fund

Investment Objective

Alger SMid Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger SMid Cap Focus Fund
Class	Y
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.81	%
Distribution and/or Shareholder Servicing (12b-1) Fees		None
Other Expenses		8.73	%
Total Annual Fund Operating Expenses		9.54	%
Fee Waiver and/or Expense Reimbursement*		(8.67	)%*
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.87	%

* Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of Class Y Shares of the Fund to .87% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher

Prospectus 20/95

or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class I				$	89			$	1,986			$	3,716			$	7,397

Portfolio Turnover

Principal Investment Strategy

Weatherbie Capital, LLC, an affiliate of Fred Alger Management, Inc. and the Fund's sub-adviser, invests in smaller cap U. S. growth companies that Weatherbie believes have enduring earnings, reasonable valuations and a distinct competitive advantage. Weatherbie invests in Foundation growth stocks and Opportunity growth stocks. Foundation growth stocks are companies led by experienced management teams, with innovative business models and the potential for high sales and earnings growth. Opportunity growth stocks are companies whose earnings may be temporarily depressed, but Weatherbie believes change is underway that can reaccelerate earnings.

Prospectus 21/95

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus 22/95

Prospectus 23/95

Performance

The following bar chart and the table beneath it provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the indicated periods compare with those of an appropriate benchmark of market performance. Class Y Shares were not offered prior to August 30, 2017. Historical performance prior to August 30, 2017 is that of the Fund's Class I Shares. Performance prior to August 6, 2007, commencement of the Class I Shares' operations, is that of the Fund's Class A Shares. Prior to August 30, 2017, the Fund followed different investment strategies under the name "Alger SMid Cap Growth Fund" and prior to March 1, 2017 was managed by different portfolio managers. Accordingly, performance prior to those dates does not reflect the Fund's current investment strategies and investment personnel. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Annual Total Return For Class I Shares* as of December 31 (%)

Best Quarter:
Q2 2009 18.02%

Worst Quarter:
Q4 2008 -28.32%

Prospectus 24/95

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			10 Years			Since 5/8/02
Class I (Inception 8/6/07)*
Return Before Taxes		37.90	%		14.00	%		6.82	%		9.39	%
Return After Taxes on Distributions		31.67	%		8.84	%		4.31	%		7.51	%
Return After Taxes on Distributions and Sale of Fund Shares		21.92	%		9.77	%		4.81	%		7.41	%
Russell 2500 Growth Index (reflects no deductions for fees, expenses or taxes)		24.46	%		15.47	%		9.62	%		9.70	%

* The returns shown are for Class I Shares, which would have had substantially similar annual returns as Class Y Shares because the Shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Performance of the Fund's Class I Shares prior to August 6, 2007 reflects the performance of the Fund's Class A Shares, as adjusted with currently applicable sales charges and operating expenses, which differ from historical charges and expenses.

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.

Sub-Adviser:

Weatherbie Capital, LLC*				H. George Dai, Ph.D. Senior Managing Director and Co-Chief Investment Officer of Weatherbie Since March 2017
				Joshua D. Bennett, CFA
				Senior Managing Director, Director of Research of Weatherbie Since March 2017
				Matthew A. Weatherbie, CFA President, Chief Executive Officer and Co-Chief Investment Officer of Weatherbie Since March 2017

* Weatherbie Capital, LLC, an affiliate of Fred Alger Management, Inc., sub-advises the Fund subject to Fred Alger Management, Inc.'s supervision and approval.

Prospectus 25/95

Shareholder Information

Purchasing and Redeeming Fund Shares

The Fund's Class Y Shares are generally subject to a minimum initial investment of $500,000. Class Y Shares are available for purchase by institutional investors such as qualified and non-qualified retirement, deferred compensation, and benefit plans, bank and trust companies, insurance companies, corporations, charitable organizations, endowments and foundations, government entities, and fund-of-funds.

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 26/95

Alger SMid Cap Focus Fund

Investment Objective

Alger SMid Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger SMid Cap Focus Fund
Class	Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses* (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.81	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.25	%
Total Annual Fund Operating Expenses		1.06	%
Fee Waiver and/or Expense Reimbursement**		(.07	)%**
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.99	%

* The expense information in the table has been restated to reflect an adjustment to the Fee Waiver and/or Expense Reimbursement that was effective on January 1, 2018.

** Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of Class Z Shares of the Fund to .99% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

Prospectus 27/95

would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	101			$	330			$	578			$	1,288

Portfolio Turnover

Principal Investment Strategy

Prospectus 28/95

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus 29/95

Small and Mid Cap Securities Risk – There may be greater risk in investing in companies with small or medium market capitalizations rather than larger, more established issuers due to such factors as more limited product lines or financial resources or lack of management depth. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Prospectus 30/95

Performance

The following bar chart and the table beneath it provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the indicated periods compare with those of an appropriate benchmark of market performance. Prior to August 30, 2017, the Fund followed different investment strategies under the name "Alger SMid Cap Growth Fund" and prior to March 1, 2017 was managed by different portfolio managers. Accordingly, performance prior to those dates does not reflect the Fund's current investment strategies and investment personnel. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2012 14.36%

Worst Quarter:
Q3 2011 -22.67%

Prospectus 31/95

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class Z (Inception 12/29/10)
Return Before Taxes		38.39	%		14.38	%		11.50	%
Return After Taxes on Distributions		32.28	%		9.27	%		7.83	%
Return After Taxes on Distributions and Sale of Fund Shares		22.19	%		10.08	%		8.29	%
Russell 2500 Growth Index (reflects no deductions for fees, expenses or taxes)		24.46	%		15.47	%		12.84	%

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.

Sub-Adviser:

Weatherbie Capital, LLC*				H. George Dai, Ph.D. Senior Managing Director and Co-Chief Investment Officer of Weatherbie Since March 2017
				Joshua D. Bennett, CFA
				Senior Managing Director, Director of Research of Weatherbie Since March 2017
				Matthew A. Weatherbie, CFA President, Chief Executive Officer and Co-Chief Investment Officer of Weatherbie Since March 2017

* The expense information in the table has been restated to reflect an adjustment to the Fee Waiver and/or Expense Reimbursement that was effective on January 1, 2018.

Prospectus 32/95

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 33/95

Alger Small Cap Growth Fund

Investment Objective

Alger Small Cap Growth Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Small Cap Growth Fund
Class	Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.81	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.27	%
Total Annual Fund Operating Expenses		1.08	%
Fee Waiver and/or Expense Reimbursement*		(.09	)%*
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.99	%

* Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of Class Z Shares of the Fund to .99% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher

Prospectus 34/95

or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	101			$	335			$	587			$	1,309

Portfolio Turnover

Principal Investment Strategy

The Fund focuses on small, fast-growing companies that Fred Alger Management, Inc. believes offer innovative products, services or technologies to a rapidly-expanding marketplace. The Fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of companies that, at the time of purchase of the securities, have total market capitalization between (1) the higher of (a) $5 billion or (b) the company in either the Russell 2000 Growth Index or the MSCI USA Small Cap Index (each, an "Index" and together, the "Indexes") with the highest capitalization, and (2) the company in either Index with the lowest capitalization, at any time during the most recent 12-month period as reported by either Index. Both Indexes are broad-based indexes of small capitalization stocks. At December 31, 2017, the market capitalization of the companies in the Indexes ranged from $6.4 million to $13.2 billion. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges.

The Fund may invest a significant portion of its assets in securities of companies conducting business within a single sector, including the health care and information technology sectors.

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

Prospectus 35/95

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Small Cap Securities Risk – There may be greater risk in investing in smaller, less seasoned companies rather than larger, more established companies due to such factors as inexperienced management and limited product lines or financial resources. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Prospectus 36/95

Healthcare Companies Risk – The Fund may have a significant portion of its assets invested in securities of healthcare companies. At times, the performance of healthcare companies will lag the performance of other industries or the broader market as a whole, and the performance of such companies may be more volatile. Healthcare companies may also be significantly affected by intense competition, aggressive pricing, government regulation, technological innovations, product obsolescence, patent considerations, product compatibility and consumer preferences.

Performance

Prospectus 37/95

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q4 2011 15.48%

Worst Quarter:
Q3 2011 -22.89%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class Z (Inception 12/29/10)
Return Before Taxes		28.64	%		12.13	%		9.76	%
Return After Taxes on Distributions		28.28	%		9.74	%		8.00	%
Return After Taxes on Distributions and Sale of Fund Shares		16.50	%		9.15	%		7.50	%
Russell 2000 Growth Index (reflects no deductions for fees, expenses or taxes)		22.17	%		15.21	%		12.19	%

Prospectus 38/95

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Amy Y. Zhang, CFA Senior Vice President and Portfolio Manager Since February 2015
				Dan C. Chung, CFA Chief Executive Officer, Chief Investment Officer and Portfolio Manager Since January 2016

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 39/95

Alger Small Cap Focus Fund

Investment Objective

Alger Small Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Small Cap Focus Fund
Class	I
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.75	%
Distribution and/or Shareholder Servicing (12b-1) Fees		.25	%
Other Expenses		.21	%
Total Annual Fund Operating Expenses		1.21	%
Fee Waiver and/or Expense Reimbursement*		(.01	)%*
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		1.20	%

* Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of Class I Shares of the Fund to 1.20% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher

Prospectus 40/95

or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class I				$	122			$	383			$	664			$	1,465

Portfolio Turnover

Principal Investment Strategy

The Fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of companies that, at the time of purchase of the securities, have total market capitalization between (1) the higher of (a) $5 billion or (b) the company in either the Russell 2000 Growth Index or the MSCI USA Small Cap Index (each, an "Index" and together, the "Indexes") with the highest capitalization, and (2) the company in either Index with the lowest capitalization, at any time during the most recent 12-month period as reported by either Index. Both Indexes are broad-based indexes of small capitalization stocks. At December 31, 2017, the market capitalization of the companies in the Indexes ranged from $6.4 million to $13.2 billion. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges. In addition, under normal market conditions, the Fund invests at least 25% of its total assets in technology companies focused in the fields of medicine and information. From time to time, the Fund may have 25% or more of its total assets invested in any one of these industries. Fred Alger Management, Inc. believes that there is very little in the field of medicine that does not use some type of medical technology and that has not been affected by new technology. Advances in technology increasingly pervade health care companies through changes in medical and surgical procedures, drugs, medical devices, and new support systems.

Prospectus 41/95

As a focus fund, the Fund intends to invest a substantial portion of its assets in a smaller number of issuers. The Fund will concentrate its portfolio in a few industries. Generally the Fund will own approximately 50 holdings. Fund holdings may occasionally exceed this number for a variety of reasons.

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus 42/95

resources. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Concentration Risk – By focusing on an industry or a group of industries, the Fund carries much greater risks of adverse developments and price movements in such industries than a fund that invests in a wider variety of industries. Because the Fund concentrates in a specific industry or group of industries, there is also the risk that the Fund will perform poorly during a slump in demand for securities of companies in such industries.

Performance

Prospectus 43/95

past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Prior to August 7, 2015, the Fund followed different investment strategies under the name "Alger Growth Opportunities Fund" and prior to February 12, 2015 was managed by a different portfolio manager. Accordingly, performance prior to those dates does not reflect the Fund's current investment strategies and investment personnel.

Annual Total Return for Class I Shares as of December 31 (%)

Best Quarter:
Q2 2009 22.64%

Worst Quarter:
Q3 2011 -22.95%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class I (Inception 3/3/08)
Return Before Taxes		28.93	%		14.91	%		9.58	%
Return After Taxes on Distributions		28.64	%		13.39	%		8.50	%
Return After Taxes on Distributions and Sale of Fund Shares		16.61	%		11.49	%		7.59	%
Russell 2000 Growth Index (reflects no deductions for fees, expenses or taxes)		22.17	%		15.21	%		10.86	%

In the foregoing table, after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state

Prospectus 44/95

and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. The after-tax returns shown may not be relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. A "Return After Taxes on Distributions and Sale of Fund Shares" may sometimes be higher than the other two return figures; this happens when there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.

Management

Investment Manager				Portfolio Manager Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Amy Y. Zhang, CFA Senior Vice President and Portfolio Manager Since February 2015

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 45/95

Alger Small Cap Focus Fund

Investment Objective

Alger Small Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Small Cap Focus Fund
Class	Y
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.75	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.76	%
Total Annual Fund Operating Expenses		1.51	%
Fee Waiver and/or Expense Reimbursement*		(.61	)%*
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.90	%

* Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of Class Y Shares of the Fund to .90% of the class's average net assets. This expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher

Prospectus 46/95

or lower, based on these assumptions you would pay the following expenses regardless of whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Y				$	92			$	417			$	766			$	1,749

Portfolio Turnover

Principal Investment Strategy

Prospectus 47/95

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus 48/95

Leverage Risk – The cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus, the Fund's net asset value could decrease more quickly than if it had not borrowed.

Performance

Prospectus 49/95

compare with those of an appropriate benchmark of market performance. Class Y Shares were not offered prior to March 1, 2017. Historical performance prior to March 1, 2017 is that of the Fund's Class Z Shares. Prior to August 7, 2015, the Fund followed different investment strategies under the name "Alger Growth Opportunities Fund" and prior to February 12, 2015 was managed by a different portfolio manager. Accordingly, performance prior to those dates does not reflect the Fund's current investment strategies and investment personnel. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2012 14.33%

Worst Quarter:
Q3 2011 -22.98%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class Z (Inception 12/29/10)*
Return Before Taxes		29.27	%		15.23	%		11.91	%
Return After Taxes on Distributions		28.98	%		13.70	%		10.36	%
Return After Taxes on Distributions and Sale of Fund Shares		16.80	%		11.75	%		9.26	%
Russell 2000 Growth Index (reflects no deductions for fees, expenses or taxes)		22.17	%		15.21	%		12.19	%

* The returns shown are for Class Z Shares, which would have substantially similar annual returns as Class Y Shares because the Shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses.

Prospectus 50/95

Management

Investment Manager				Portfolio Manager Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Amy Y. Zhang, CFA Senior Vice President and Portfolio Manager Since February 2015

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 51/95

Alger Small Cap Focus Fund

Investment Objective

Alger Small Cap Focus Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Small Cap Focus Fund
Class	Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.75	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.15	%
Total Annual Fund Operating Expenses		.90	%

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses regardless of whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	92			$	287			$	498			$	1,108

Portfolio Turnover

Prospectus 52/95

Principal Investment Strategy

The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

The Fund can invest in foreign securities.

Prospectus 53/95

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus 54/95

the Fund will perform poorly during a slump in demand for securities of companies in such industries.

Leverage Risk – The cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus, the Fund's net asset value could decrease more quickly than if it had not borrowed.

Performance

Prospectus 55/95

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2012 14.33%

Worst Quarter:
Q3 2011 -22.98%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since Inception
Class Z (Inception 12/29/10)
Return Before Taxes		29.27	%		15.23	%		11.91	%
Return After Taxes on Distributions		28.98	%		13.70	%		10.36	%
Return After Taxes on Distributions and Sale of Fund Shares		16.80	%		11.75	%		9.26	%
Russell 2000 Growth Index (reflects no deductions for fees, expenses or taxes)		22.17	%		15.21	%		12.19	%

Prospectus 56/95

Management

Investment Manager				Portfolio Manager Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Amy Y. Zhang, CFA Senior Vice President and Portfolio Manager Since February 2015

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

Prospectus 57/95

Alger Health Sciences Fund

Investment Objective

Alger Health Sciences Fund seeks long-term capital appreciation.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Class Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses* (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.55	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.31	%
Total Annual Fund Operating Expenses		.86	%
Fee Waiver and/or Expense Reimbursement**		(.11	)%**
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.75	%

* The expense information in the table has been restated to reflect a reduction in management fees and an adjustment to the Fee Waiver and/or Expense Reimbursement that were effective on January 1, 2018.

** Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of the Fund's Class Z Shares to .75% of the class's average net assets. The expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the contractual expense limitation agreed to by Fred Alger Management, Inc. Although your actual costs may be higher

Prospectus 58/95

or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	77			$	263			$	466			$	1,051

Portfolio Turnover

Principal Investment Strategy

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of companies of any market capitalization that are engaged in the health sciences sector. Equity securities include common or preferred stocks that are listed on U.S. or foreign exchanges. A company will be considered to be engaged in the health sciences sector if it derives at least 50% of its earnings or revenues from, or devotes at least 50% of its assets to, activities in any area of the health sciences sector, including health care services, pharmaceuticals, medical equipment and supplies and applied research and development. Such companies include, but are not limited to:

• hospitals, clinical test laboratories, convalescent and mental health care facilities, home care providers, and companies that supply services to any of the foregoing;

• companies involved in pharmaceuticals, biotechnology, biochemistry and diagnostics; and

• producers and manufacturers of medical, dental and optical supplies and equipment.

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The Fund can also invest in privately placed securities, which are securities acquired in non-public offerings for which there is no readily available market.

The Fund can invest in foreign securities.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Leverage Risk – The cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in

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value; thus, the Fund's net asset value could decrease more quickly than if it had not borrowed.

Privately Placed Securities Risk – A private placement is an offering of a company's securities that is not registered with the SEC and is not offered to the public. Less information may be available about companies that make private placements than about publicly offered companies and such companies may not be subject to the disclosure and other investor protection requirements that would be applicable if their securities were publicly traded. The sale or transfer of privately placed securities may be limited or prohibited by contract or law and such investments are generally considered to be illiquid. Privately placed securities are generally fair valued as they are not traded frequently. The Fund may be required to hold such positions for several years, if not longer, regardless of valuation, which may cause the Fund to be less liquid.

Performance

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performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.

Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2017 16.43%

Worst Quarter:
Q1 2016 -15.96%

Average Annual Total Return as of December 31, 2017

	1 Year			Since Inception (5/28/15)
Class Z
Return Before Taxes		37.75	%		6.90	%
Return After Taxes on Distributions		36.76	%		4.82	%
Return After Taxes on Distributions and Sale of Fund Shares		22.17	%		4.76	%
S&P 500 Index (reflects no deductions for fees, expenses or taxes)		21.83	%		11.66	%
Russell 3000 Healthcare Index (reflects no deductions for fees, expenses or taxes)		23.13	%		5.34	%

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retirement accounts. A "Return After Taxes on Distributions and Sale of Fund Shares" may sometimes be higher than the other two return figures; this happens when there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.

Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Dan C. Chung, CFA Chief Executive Officer, Chief Investment Officer and Portfolio Manager Since October 2005
				Teresa McRoberts Senior Vice President, Senior Analyst and Portfolio Manager Since February 2015

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

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Alger Growth & Income Fund

Investment Objective

Alger Growth & Income Fund seeks to provide capital appreciation and current income.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

	Alger Growth & Income Fund
Class	Z
Shareholder Fees (fees paid directly from your investment)		None
Annual Fund Operating Expenses* (expenses that you pay each year as a percentage of the value of your investment)
Management Fees		.50	%
Distribution and/or Service (12b-1) Fees		None
Other Expenses		.31	%
Total Annual Fund Operating Expenses		.81	%
Fee Waiver and/or Expense Reimbursement**		(.12	)%**
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		.69	%

** Fred Alger Management, Inc. has contractually agreed to waive fees or to reimburse Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the annual operating expenses of the Fund's Class Z Shares to .69% of the class's average net assets. The expense reimbursement may only be amended or terminated prior to its expiration date by agreement between Fred Alger Management, Inc. and the Fund's Board of Trustees, and will terminate automatically in the event of termination of the Investment Advisory Agreement. Fred Alger Management, Inc. may, during the one-year term of the expense reimbursement contract, recoup any expenses waived or reimbursed pursuant to the expense reimbursement contract to the extent that such recoupment would not cause the expense ratio to exceed the lesser of the stated limitation in effect at the time of (i) the waiver or reimbursement and (ii) the recoupment.

Example

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would pay the following expenses whether or not you redeemed your shares at the end of each period:

				1 Year				3 Years				5 Years				10 Years
Class Z				$	70			$	247			$	438			$	991

Portfolio Turnover

Principal Investment Strategy

The Fund invests primarily in equity securities such as common or preferred stocks which Fred Alger Management, Inc. believes offer opportunities for capital appreciation and which also pay dividends. In considering such companies, Fred Alger Management, Inc, classifies them into three categories: Dividend Leaders – companies that generate high dividend yields; Dividend Growers – companies that have a history of strong and consistent dividend growth; and Kings of Cash Flow – companies that have strong potential for generating capital appreciation and the ability to return significant amounts of cash to investors as a result of their free cash flow. The Fund intends to invest at least 65% of its total assets in dividend-paying equity securities. The Fund may invest up to 35% of its total assets in equity securities that do not pay dividends or in money market instruments and repurchase agreements. The Fund focuses on growing companies that, at the time of purchase of the securities, have a market capitalization equal to or greater than the market capitalization of companies included in the S&P 500 Index, as reported by the index as of the most recent quarter-end. This index is designed to track the performance of large-capitalization stocks. At December 31, 2017, the market capitalization of the companies in this index ranged from $2.7 billion to $868.9 billion.

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The Fund's portfolio manager(s) may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive.

Principal Risks

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Equity Securities Risk – As with any portfolio that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. The Fund's price per share will fluctuate due to changes in the market prices of its investments. Also, the Fund's investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds. In addition, there are special risks associated with investing in preferred securities, including deferral and omission of distributions, subordination to bonds and other debt securities in a company's capital structure, limited liquidity, limited voting rights and special redemption rights. The market value of preferred stocks is generally more sensitive to changes in interest rates than the market value of common stocks.

Income-Producing Securities Risk – Companies may cut or fail to declare dividends due to market downturns or other reasons.

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developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Performance

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Annual Total Return for Class Z Shares as of December 31 (%)

Best Quarter:
Q1 2013 10.60%

Worst Quarter:
Q3 2015 -6.70%

Average Annual Total Return as of December 31, 2017

	1 Year			5 Years			Since 3/1/12
Class Z (Inception 3/1/12)
Return Before Taxes		21.00	%		14.60	%		13.21	%
Return After Taxes on Distributions		19.77	%		13.27	%		11.95	%
Return After Taxes on Distributions and Sale of Fund Shares		12.22	%		11.17	%		10.11	%
S&P 500 Index (reflects no deductions for fees, expenses or taxes)		21.83	%		15.79	%		14.48	%

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Management

Investment Manager				Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio
Fred Alger Management, Inc.				Dan C. Chung, CFA Chief Executive Officer, Chief Investment Officer and Portfolio Manager Since January 2011
				Gregory S. Adams, CFA Senior Vice President, Director of Quantitative & Risk Management and Portfolio Manager Since April 2012

Shareholder Information

Purchasing and Redeeming Fund Shares

Investors may purchase or redeem Fund shares on any business day through a financial intermediary.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

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Investment Objectives, Principal Investment Strategies and Related Risks

The investment objective, principal strategy and primary risks of each Fund are discussed individually above. Each Fund other than Alger Capital Appreciation Fund and Alger Growth & Income Fund has adopted a policy to invest at least 80% of its assets in specified securities appropriate to its name (as described in the Fund's Summary Section in this Prospectus) and to provide its shareholders with at least 60 days' prior notice of any change with respect to this policy. Each Fund's investment objective may be changed by the Board of Trustees without shareholder approval. A Fund will provide its shareholders with at least 60 days' prior notice of any change to its investment objective.

All of a Fund's share classes invest in the same portfolio of securities. Performance of each share class will vary from the performance of the Fund's other share classes due to the differences in charges or expenses. Remember that a Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future.

Each index used in the Summary Sections is a broad-based index designed to track a particular market or market segment. No expenses, fees or taxes are reflected in the returns for the indexes, which are unmanaged. All returns for the indexes assume reinvestment of dividends and interest of the underlying securities that make up the respective index.

• Russell 1000 Growth Index: An unmanaged index designed to measure the performance of the largest 1000 capitalization companies in the Russell 3000 Index with higher price-to-book ratios and higher forecasted growth values.

• Russell 2000 Growth Index: An unmanaged index designed to measure the performance of the 2,000 smallest companies in the Russell 3000 Index with higher price-to-book ratios and higher forecasted growth values.

• Russell 2500 Growth Index: An unmanaged index designed to measure the performance of the 2,500 smallest companies in the Russell 3000 Index with higher price-to-book ratios and higher forecasted growth values.

• Russell 3000 Healthcare Index: An index designed to measure the performance of all healthcare holdings included in the Russell 3000 Index, which represents the 3,000 largest U.S. companies based on total market capitalization.

• Russell Midcap Growth Index: An index of common stocks designed to track performance of medium-capitalization companies with greater than average growth orientation.

• S&P 500 Index: An index of large company common stocks considered to be representative of the U.S. stock market.

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Additional Information About the Funds' Investment Strategies and Investments

Investment Objectives

Each of Alger Capital Appreciation Fund, Alger Mid Growth Fund, Alger SMid Cap Focus Fund, Alger Small Cap Growth Fund, Alger Small Cap Focus Fund and Alger Health Sciences Fund seeks long-term capital appreciation. Alger Growth & Income Fund seeks to provide capital appreciation and current income.

Principal Investment Strategies and Related Risks

The following are each Fund's investment process, and principal investment strategies and related risks. Each Fund may invest in other securities that are not its principal strategy, and such strategies and related risks are described in more detail in the Fund's Statement of Additional Information.

Each Fund invests primarily in equity securities. Each Fund's investments in equity securities are primarily in common or preferred stocks, but its equity investments also may include securities convertible into or exchangeable for equity securities (including warrants and rights) and depositary receipts. Each Fund invests primarily in companies whose securities are traded on U.S. or foreign exchanges. The Funds invest primarily in "growth" stocks. Fred Alger Management, Inc. ("Alger Management" or the "Manager") believes that these companies tend to fall into one of two categories:

• High Unit Volume Growth

Vital, creative companies which offer goods or services to a rapidly-expanding marketplace. They include both established and emerging firms, exercising market dominance, offering new or improved products, or simply fulfilling an increased demand for an existing product line.

• Positive Life Cycle Change

Companies experiencing a major change which is expected to produce advantageous results. These changes may be as varied as new management, products or technologies; restructuring or reorganization; regulatory change; or merger and acquisition.

Each Fund other than Alger Capital Appreciation Fund and Alger Health Sciences Fund must take into account a company's market capitalization when considering it for investment. The market capitalization of a company is its price per share multiplied by its number of outstanding shares.

Alger Capital Appreciation Fund

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Alger Mid Cap Growth Fund

Alger SMid Cap Focus Fund

Alger Small Cap Growth Fund

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Alger Small Cap Focus Fund

Alger Health Sciences Fund

Alger Growth & Income Fund

The Fund invests primarily in equity securities such as common or preferred stocks which Fred Alger Management, Inc. believes offer opportunities for capital appreciation and which also pay dividends. In considering such companies, Fred Alger Management, Inc. classifies them into three categories: Dividend Leaders – companies that generate high dividend yields; Dividend Growers – companies that have a history of strong and consistent dividend growth; and Kings of Cash Flow – companies that have strong potential for generating capital appreciation and the ability to return significant amounts of cash to investors as a result of their free cash flow. The Fund intends to invest at least 65% of its total assets in dividend paying equity securities. The Fund may invest up to 35% of its total assets in equity securities that do not pay dividends or in money market instruments and repurchase agreements. The Fund focuses on growing companies that, at the time of purchase of the securities, have a market capitalization equal to or greater

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than the market capitalization of companies included in the S&P 500 Index, as reported by the index as of the most recent quarter-end. This index is designed to track the performance of large-capitalization stocks. At December 31, 2017, the market capitalization of the companies in this index ranged from $2.7 billion to $868.9 billion.

Principal Risks

Investment Risk

An investment in a Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Market Risk

Your investment in Fund shares represents an indirect investment in the securities owned by the Fund. The value of these securities, like other investments, may move up or down, sometimes rapidly and unpredictably. Your Fund shares at any point in time may be worth less than what you invested, even after taking into account the reinvestment of Fund dividends and distributions.

Equity Securities Risk

As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. Each Fund's price per share will fluctuate due to changes in the market prices of its investments. Because stock markets tend to move in cycles, stock prices overall may decline. A particular stock's market value may decline as a result of general market conditions that are not related to the issuing company (e.g., adverse economic conditions or investor sentiment) or due to factors that affect the particular company (e.g., management performance or factors affecting the industry). Also, a Fund's investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds.

Growth Stocks Risk

Prices of growth stocks tend to be higher in relation to their companies' earnings and may be more sensitive to market, political and economic developments than other stocks, making their prices more volatile. An investment in a Fund may be better suited to investors who seek long-term capital growth and can tolerate fluctuations in their investment's value. Expected growth may not be realized.

Small Cap Securities Risk

There may be greater risk in investing in smaller, less seasoned companies rather than larger, more established companies due to such factors as inexperienced management and limited product lines or financial resources. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

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Mid Cap Securities Risk

There may be greater risk in investing in medium-capitalization companies rather than larger, more established companies due to such factors as inexperienced management and limited product lines or financial resources. It may also be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

Leverage Risk

Alger Capital Appreciation Fund, Alger SMid Cap Focus Fund and Alger Small Cap Focus Fund can leverage, that is, borrow money to buy additional securities. By borrowing money, the Funds have the potential to increase their returns if the increase in the value of the securities purchased exceeds the cost of borrowing, including interest paid on the money borrowed. There is a risk that the cost of borrowing money to leverage may exceed the returns for the securities purchased or that the securities purchased may actually go down in value; thus the Fund's net asset value could decrease more quickly than if it had not borrowed.

Foreign Securities Risk

Investing in foreign securities involves risks related to the political, social and economic conditions of foreign countries, particularly emerging market countries. These risks may include political instability, exchange control regulations, expropriation, lack of comprehensive information, national policies restricting foreign investment, currency fluctuations, less liquidity, undiversified and immature economic structures, inflation and rapid fluctuations in inflation, withholding or other taxes, and operational risks. There may be less stringent government supervision and oversight of foreign markets than in the United States. There may be less corporate financial information publicly available, less stringent investor protection and disclosure standards, and differing auditing and legal standards.

Investment in foreign currencies is subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedged positions, that the U.S. dollar will decline relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time. A decline in the value of foreign currencies relative to the U.S. dollar will reduce the value of securities held by a Fund and denominated in those currencies. Foreign currencies also are subject to risks caused by inflation, interest rates, budget deficits and low savings rates, political factors and government controls.

Less Diversified Portfolio Risk

Each of Alger SMid Cap Focus Fund and Alger Small Cap Focus Fund may have a more concentrated portfolio than other funds, so it may be more vulnerable to changes in the market value of a single issuer and may be more susceptible to risks associated with a single economic, political or regulatory occurrence than a fund that has a more diversified portfolio. The Fund may have substantial holdings within a

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particular sector, and companies in similar industries may be similarly affected by particular economic or market events.

Sector Risk

Each of Alger Capital Appreciation Fund, Alger Mid Cap Growth Fund, Alger SMid Cap Focus Fund, Alger Small Cap Growth Fund, Alger Small Cap Focus Fund, Alger Health Sciences Fund and Alger Growth & Income Fund may have a significant portion of its assets invested in securities of companies conducting business within a single sector. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

The Fund may be more susceptible to particular risks that may affect companies in the information technology sector and technology-related sectors than if it were invested in a wider variety of companies in unrelated sectors. At times, the performance of such companies will lag the performance of other industries or the broader market as a whole. Certain technology related companies may face special risks that their products or services may not prove to be commercially successful. Technology related companies are also strongly affected by worldwide scientific or technological developments. As a result, their products may rapidly become obsolete. Such companies are also often subject to governmental regulation and may, therefore, be adversely affected by governmental policies. These factors may lead to limited earnings and/or failing profit margins. As a result, the value of technology related companies' securities may fall or fail to rise. In addition, many technology related companies have limited operating histories and prices of these companies' securities have historically been more volatile than other securities, especially over the short term.

The Fund may be more susceptible to particular risks that may affect companies in the healthcare sector than if it were invested in a wider variety of companies in unrelated sectors. At times, the performance of such companies will lag the performance of other industries or the broader market as a whole, and the performance of such companies may be more volatile. The healthcare field is subject to substantial governmental regulation and may, therefore, be adversely affected by changes in governmental policies. These factors may lead to limited earnings and/or failing profit margins. As a result, the value of healthcare companies' securities may fall or fail to rise. In addition, companies in the healthcare sector can be significantly affected by intense competition, aggressive pricing, technological innovations, product obsolescence, patent considerations, product compatibility and consumer preferences.

Concentration Risk

By focusing on an industry or a group of industries, the each of Alger Small Cap Focus Fund and Alger Health Sciences Fund carries much greater risks of adverse developments and price movements in such industries than a fund that invests in a wider variety of industries. Because the Fund concentrates in a specific industry or

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group of industries, there is also the risk that the Fund will perform poorly during a slump in demand for securities of companies in such industries.

Portfolio Turnover (Active Trading) Risk

If the Fund engages in active trading of portfolio securities, it may incur increased transaction costs and brokerage commissions, both of which can lower the actual return on an investment. Active trading may also increase short-term gains and losses, which may affect the taxes a shareholder has to pay.

Income-Producing Securities Risk

Alger Growth & Income Fund invests in income-producing securities. Companies may cut or fail to declare dividends due to market downturns or other reasons.

Illiquid Investments Risk

Alger Health Sciences Fund invests in illiquid investments. Illiquid investments are investments that the Fund cannot sell within seven days at approximately current value. If the Fund holds illiquid investments it may be unable to quickly sell them or may be able to sell them only at a price below current value. Illiquid investments may be more difficult to value.

Restricted Securities Risk

Alger Health Sciences Fund invests in restricted securities (i.e., securities which are subject to legal or contractual restrictions on their resale), including restricted securities governed by Rule 144A under the Securities Act of 1933, as amended. The Fund may not invest more than 15% of its net assets in "illiquid" securities, which include certain restricted securities, including privately placed securities, other securities for which there is no readily available market and repurchase agreements with maturities of greater than seven days; however, restricted securities that are determined by the Board of Trustees of the Trust to be liquid are not subject to this limitation.

Temporary Defensive and Interim Investments

In times of adverse or unstable market, economic or political conditions, a Fund may invest up to 100% of its assets in cash, high-grade bonds, or cash equivalents (such as commercial paper or money market instruments) for temporary defensive reasons. This is to attempt to protect the Fund's assets from a temporary, unacceptable risk of loss, rather than directly to promote the Fund's investment objective. A Fund may also hold these types of securities in an amount up to 15% of net assets (35% of net assets, in the case of Alger Growth & Income Fund), pending the investment of proceeds from the sale of Fund shares or portfolio securities or to meet anticipated redemptions of Fund shares. A Fund may not achieve its investment objective while in a temporary defensive or interim position.

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Management and Organization

Manager

Fred Alger Management, Inc.
360 Park Avenue South
New York, NY 10010

The Manager has been an investment adviser since 1964, and manages investments totaling (at December 31, 2017) approximately $23.1 billion ($15.9 billion in mutual fund assets as well as $7.2 billion in other assets). The Manager makes investment decisions for each Fund and continuously reviews its investment program. These management responsibilities are subject to the supervision of the Board of Trustees. The Funds pay the Manager advisory fees at the following annual rates based on a percentage of average daily net assets: Alger Capital Appreciation Fund – .81% for assets up to $2 billion, .65% for assets between $2 billion and $3 billion, .60% for assets between $3 billion and $4 billion, .55% for assets between $4 billion and $5 billion, and .45% for assets in excess of $5 billion; Alger Mid Cap Growth Fund – .76% for assets up to $1 billion and .70% for assets in excess of $1 billion; Alger SMid Cap Focus Fund and Alger Small Cap Growth Fund – .81% for assets up to $1 billion and .75% for assets in excess of $1 billion; Alger Small Cap Focus Fund – .75%; Alger Health Sciences Fund – .55%, and Alger Growth & Income Fund – .50%.

The actual advisory fee rate paid by Alger Capital Appreciation Fund for the period ended October 31, 2017 was .77% of average daily net assets. The actual advisory fee rate paid by Alger Mid Cap Growth Fund for the period ended October 31, 2017 was .76% of average daily net assets. The actual advisory fee rate paid by Alger SMid Cap Focus Fund for the period ended October 31, 2017 was .81% of average daily net assets. The actual advisory fee rate paid by Alger Small Cap Growth Fund for the period ended October 31, 2017 was .81% of average daily net assets. The actual advisory fee rate paid by Alger Small Cap Focus Fund for the period ended October 31, 2017 was .75% of average daily net assets. The actual advisory fee rate paid by Alger Health Sciences Fund for the period ended October 31, 2017 was .81% of average daily net assets. The actual advisory fee rate paid by Alger Growth & Income Fund for the period ended October 31, 2017 was .585% of average daily net assets.

Fred Alger Management, Inc. has contractually agreed to waive fees or reimburse Alger Small Cap Focus Fund expenses (excluding acquired fund fees and expenses, dividend expense on short sales, borrowing costs, interest, taxes, brokerage and extraordinary expenses) through February 28, 2019 to the extent necessary to limit the total annual fund operating expenses of the Class Z Shares of the Fund to 0.99% of the class's average daily net assets.

A discussion of the Trustees' basis for the approving the investment advisory agreement with respect to each Fund is available in the Fund's annual report to shareholders for its most recent October 31 fiscal year end.

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Sub-Adviser

Weatherbie Capital, LLC
265 Franklin Street, 16th Floor
Boston, Massachusetts 02110

The Manager has engaged Weatherbie Capital, LLC ("Weatherbie" or the "Sub-Adviser"), an affiliate of the Manager, to serve as Alger SMid Cap Focus Fund's sub-adviser under a sub-investment advisory agreement between the Manager and the Sub-Adviser. Weatherbie is a registered investment adviser formed in 1995. As of December 31, 2017, Weatherbie had approximately $1.3 billion in assets under management. Weatherbie sub-advises the Fund subject to the Manager's supervision and approval. The Manager pays a sub-advisory fee to the Sub-Adviser out of its own resources at no additional charge to the Fund.

Portfolio Managers Jointly and Primarily Responsible for Day-to-Day Management of the Fund's Portfolio

Fund	Portfolio Managers	Since
Alger Capital Appreciation Fund	Ankur Crawford, Ph.D. Patrick Kelly, CFA	June 2015 September 2004
Alger Mid Cap Growth Fund*	Dan C. Chung, CFA Teresa McRoberts Christopher R. Walsh, CFA	January 2018 February 2015 February 2013
Alger SMid Cap Focus Fund	H. George Dai, Ph.D. Joshua D. Bennett, CFA Matthew A. Weatherbie, CFA	March 2017 March 2017 March 2017
Alger Small Cap Growth Fund	Amy Y. Zhang, CFA Dan C. Chung, CFA	February 2015 January 2016
Alger Small Cap Focus Fund	Amy Y. Zhang, CFA	February 2015
Alger Health Sciences Fund	Dan C. Chung, CFA Teresa McRoberts	October 2005 February 2015
Alger Growth & Income Fund	Dan C. Chung, CFA Gregory S. Adams, CFA	January 2011 April 2012

• Mr. Chung, the Manager's Chief Investment Officer, Ms. McRoberts and Mr. Walsh are each responsible for the management of a portion of the Fund's portfolio. Mr. Chung, for his portion, coordinates and oversees portfolio allocations by members of the Manager's analyst team for Alger Mid Cap Growth Fund. Each analyst is allocated a percentage of the Fund's total assets, is responsible for the management of that portion of the Fund's portfolio, and has such allocation rebalanced on a periodic basis by Mr. Chung.

• Mr. Adams has been employed by the Manager since 2006. He became a Senior Vice President and the Director of Quantitative & Risk Management in 2006, and a portfolio manager in 2012. From 2006 through 2012, Mr. Adams was a Senior Analyst.

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• Mr. Bennett is a Senior Managing Director, Director of Research of Weatherbie. He joined Weatherbie in 2007.

• Mr. Chung has been employed by the Manager since 1994. He became a portfolio manager in 2000, Chief Investment Officer in 2001, President in 2003, and Chief Executive Officer in 2006.

• Ms. Crawford has been employed by the Manager since 2004. She became a portfolio manager and a Senior Vice President in 2010. She served as a Vice President and an Analyst from 2007 to 2010, and a Senior Analyst from 2010 to 2016.

• Mr. Dai is a Senior Managing Director and Co-Chief Investment Officer of Weatherbie. He joined Weatherbie in 2001.

• Mr. Kelly has been employed by the Manager since 1999. He became a portfolio manager in 2004, an Executive Vice President in 2008 and Head of Alger Capital Appreciation and Spectra Strategies in 2015.

• Ms. McRoberts has been employed by the Manager since 2015 as a Senior Vice President, a Senior Analyst and a Portfolio Manager. Prior to joining the Manager, she was a founder and partner of Bienville Health Science Partners, LP from September 2013 to January 2015. Ms. McRoberts was self-employed from November 2009 to September 2013.

• Mr. Walsh has been employed by the Manager since 2001. He became a portfolio manager and a Senior Analyst in 2007, and a Senior Vice President in 2008.

• Mr. Weatherbie is President, Chief Executive Officer and Co-Chief Investment Officer of Weatherbie. He founded Weatherbie in 1995.

• Ms. Zhang has been employed by the Manager since 2015 as a Senior Vice President and Portfolio Manager. Prior to joining the Manager, she was a Managing Director and Senior Portfolio Manager at Brown Capital Management, Inc. from 2002 to 2015.

The Funds' Statement of Additional Information provides additional information about the portfolio managers' compensation structure, other accounts managed by the portfolio managers, and the portfolio managers' ownership of Fund securities.

Administrator

Pursuant to a separate Fund Administration Agreement, the Manager provides administrative services to each Fund, including, but not limited to: providing office space, telephone, office equipment and supplies; authorizing expenditures and approving bills for payment on behalf of the Fund; supervising preparation of periodic shareholder reports, notices and other shareholder communications; supervising the daily pricing of the Fund's investment portfolios and the publication of the net asset value of the Fund's shares, earnings reports and other financial data; monitoring relationships with organizations providing services to the Fund, including the Fund's custodian, blue sky agent and printers; providing trading desk facilities for the Fund; and supervising compliance by the Fund with recordkeeping and periodic

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reporting requirements under the Investment Company Act of 1940, as amended. Each Fund pays the Administrator a fee at the annual rate of .0275% of the Fund's average daily net assets.

Pursuant to a separate Shareholder Administrative Services Agreement, the Manager also supervises the Fund's transfer agent, DST Asset Manager Solutions, Inc. (the "Transfer Agent"), and provides certain shareholder administrative services to the Fund. The Fund pays the Manager a shareholder administrative services fee at the annual rate of 0.01% of net assets with respect to Class I, Y, and Z Shares.

For more information, please see the Shareholder Information section beginning on Page A-1.

Hypothetical Investment and Expense Information

Hypothetical investment and expense information, which is not required to be included in this Prospectus by the Securities and Exchange Commission, is presented in the chart below. This information is intended to reflect the annual and cumulative effect of a Fund's expenses, including investment advisory fees and other Fund costs, on each Fund's total return over a 10-year period. The example assumes the following:

• You invest $10,000 in the Fund and hold it for the entire 10-year period; and

• Your investment has a 5% return before expenses each year.

There is no assurance that the annual expense ratio will be the expense ratio for any Fund classes for any of the years shown. To the extent that the Manager and any of its affiliates make any fee waivers and/or expense reimbursements pursuant to a voluntary or other contractual arrangement, your actual expenses may be less. This is only a hypothetical presentation made to illustrate what expenses and returns would be under the above scenarios. Your actual returns and expenses are likely to differ (higher or lower) from those shown below.

Alger Capital Appreciation Fund

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%		0.88	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.12	%		8.41	%		12.88	%		17.53	%		22.37	%		27.41	%		32.66	%		38.13	%		43.82	%		49.74	%
End Investment Balance	$	10,412		$	10,841		$	11,288		$	11,753		$	12,237		$	12,741		$	13,266		$	13,813		$	14,382		$	14,974
Annual Expense	$	90		$	94		$	97		$	101		$	106		$	110		$	114		$	119		$	124		$	129

Prospectus 81/95

Alger Mid Cap Growth Fund

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		1.05	%		1.07	%		1.07	%		1.07	%		1.07	%		1.07	%		1.07	%		1.07	%		1.07	%		1.07	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		3.95	%		8.04	%		12.28	%		16.69	%		21.28	%		26.05	%		31.00	%		36.15	%		41.50	%		47.06	%
End Investment Balance	$	10,395		$	10,804		$	11,228		$	11,669		$	12,128		$	12,605		$	13,100		$	13,615		$	14,150		$	14,706
Annual Expense	$	107		$	113		$	118		$	123		$	127		$	132		$	138		$	143		$	149		$	154

Alger SMid Cap Focus Fund

Class I	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%		1.35	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		3.65	%		7.43	%		11.35	%		15.42	%		19.63	%		24.00	%		28.52	%		33.22	%		38.08	%		43.12	%
End Investment Balance	$	10,365		$	10,743		$	11,135		$	11,542		$	11,963		$	12,400		$	12,852		$	13,322		$	13,808		$	14,312
Annual Expense	$	137		$	142		$	148		$	153		$	159		$	164		$	170		$	177		$	183		$	190

Class Y	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.87	%		9.54	%		9.54	%		9.54	%		9.54	%		9.54	%		9.54	%		9.54	%		9.54	%		9.54	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.13	%		-0.60	%		-5.11	%		-9.42	%		-13.53	%		-17.46	%		-21.20	%		-24.78	%		-28.20	%		-31.46	%
End Investment Balance	$	10,413		$	9,940		$	9,489		$	9,058		$	8,647		$	8,254		$	7,880		$	7,522		$	7,180		$	6,854
Annual Expense	$	89		$	971		$	927		$	885		$	845		$	806		$	770		$	735		$	701		$	669

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.99	%		1.06	%		1.06	%		1.06	%		1.06	%		1.06	%		1.06	%		1.06	%		1.06	%		1.06	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.01	%		8.11	%		12.37	%		16.79	%		21.40	%		26.18	%		31.15	%		36.32	%		41.69	%		47.27	%
End Investment Balance	$	10,401		$	10,811		$	11,237		$	11,679		$	12,140		$	12,618		$	13,115		$	13,632		$	14,169		$	14,727
Annual Expense	$	101		$	112		$	117		$	121		$	126		$	131		$	136		$	142		$	147		$	153

Alger Small Cap Growth Fund

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.99	%		1.08	%		1.08	%		1.08	%		1.08	%		1.08	%		1.08	%		1.08	%		1.08	%		1.08	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.01	%		8.09	%		12.32	%		16.73	%		21.30	%		26.06	%		31.00	%		36.13	%		41.47	%		47.02	%
End Investment Balance	$	10,401		$	10,809		$	11,232		$	11,673		$	12,130		$	12,606		$	13,100		$	13,613		$	14,147		$	14,702
Annual Expense	$	101		$	115		$	119		$	124		$	129		$	134		$	139		$	144		$	150		$	156

Prospectus 82/95

Alger Small Cap Focus Fund

Class I	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		1.20	%		1.21	%		1.21	%		1.21	%		1.21	%		1.21	%		1.21	%		1.21	%		1.21	%		1.21	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		3.80	%		7.73	%		11.82	%		16.06	%		20.45	%		25.02	%		29.76	%		34.67	%		39.78	%		45.08	%
End Investment Balance	$	10,380		$	10,773		$	11,182		$	11,606		$	12,045		$	12,502		$	12,976		$	13,467		$	13,978		$	14,508
Annual Expense	$	122		$	128		$	133		$	138		$	143		$	149		$	154		$	160		$	166		$	172

Class Y	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.90	%		1.51	%		1.51	%		1.51	%		1.51	%		1.51	%		1.51	%		1.51	%		1.51	%		1.51	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.10	%		7.73	%		11.49	%		15.38	%		19.41	%		23.58	%		27.89	%		32.35	%		36.97	%		41.75	%
End Investment Balance	$	10,410		$	10,773		$	11,149		$	11,538		$	11,941		$	12,358		$	12,789		$	13,235		$	13,697		$	14,175
Annual Expense	$	92		$	160		$	166		$	171		$	177		$	183		$	190		$	196		$	203		$	210

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%		0.90	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.10	%		8.37	%		12.81	%		17.44	%		22.25	%		27.26	%		32.48	%		37.91	%		43.57	%		49.45	%
End Investment Balance	$	10,410		$	10,837		$	11,281		$	11,744		$	12,225		$	12,726		$	13,248		$	13,791		$	14,357		$	14,945
Annual Expense	$	92		$	96		$	100		$	104		$	108		$	112		$	117		$	122		$	127		$	132

Alger Health Sciences Fund

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.75	%		0.86	%		0.86	%		0.86	%		0.86	%		0.86	%		0.86	%		0.86	%		0.86	%		0.86	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.25	%		8.57	%		13.06	%		17.74	%		22.62	%		27.69	%		32.98	%		38.48	%		44.22	%		50.19	%
End Investment Balance	$	10,425		$	10,857		$	11,306		$	11,774		$	12,262		$	12,769		$	13,298		$	13,848		$	14,422		$	15,019
Annual Expense	$	77		$	92		$	95		$	99		$	103		$	108		$	112		$	117		$	122		$	127

Alger Growth & Income Fund

Class Z	Year 1			Year 2			Year 3			Year 4			Year 5			Year 6			Year 7			Year 8			Year 9			Year 10
Expense Ratio		0.69	%		0.81	%		0.81	%		0.81	%		0.81	%		0.81	%		0.81	%		0.81	%		0.81	%		0.81	%
Cumulative Gross Return		5.00	%		10.25	%		15.76	%		21.55	%		27.63	%		34.01	%		40.71	%		47.75	%		55.13	%		62.89	%
Cumulative Net Return		4.31	%		8.68	%		13.23	%		17.98	%		22.92	%		28.07	%		33.44	%		39.03	%		44.86	%		50.92	%
End Investment Balance	$	10,431		$	10,868		$	11,323		$	11,798		$	12,292		$	12,807		$	13,344		$	13,903		$	14,486		$	15,092
Annual Expense	$	70		$	86		$	90		$	94		$	98		$	102		$	106		$	110		$	115		$	120

Prospectus 83/95

Financial Highlights

The financial highlights table is intended to help you understand each Fund's financial performance for the periods shown. Certain information reflects financial results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in the Fund (assuming reinvestment of all dividends and distributions). The information in the table for the fiscal years ended October 31 has been audited by Deloitte & Touche LLP whose report, along with each Fund's financial statements, is included in the Annual Report, which is available upon request.

Prospectus 84/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Capital Appreciation Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	20.48		$	22.15		$	23.35		$	21.31		$	16.68
Income from Investment Operations:
Net investment income (i)		0.05			0.06			0.03			0.04			0.11
Net realized and unrealized gain on investments		6.10			(0.06	)		2.00			3.53			4.76
Total from investment operations		6.15			—			2.03			3.57			4.87
Dividends from net investment income		—			—			—			—			(0.17	)
Distributions from net realized gains		(0.17	)		(1.67	)		(3.23	)		(1.53	)		(0.07	)
Net asset value, end of period	$	26.46		$	20.48		$	22.15		$	23.35		$	21.31
Total return (ii)		30.25	%		(0.08	)%		9.54	%		17.68	%		29.58	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	983,006		$	735,889		$	620,355		$	286,186		$	183,790
Ratio of gross expenses to average net assets		0.88	%		0.89	%		0.90	%		0.93	%		0.93	%
Ratio of expense reimbursements to average net assets		—			—			—			—			—
Ratio of net expenses to average net assets		0.88	%		0.89	%		0.90	%		0.93	%		0.93	%
Ratio of net investment income (loss) to average net assets		0.23	%		0.30	%		0.12	%		0.16	%		0.58	%
Portfolio turnover rate		72.99	%		103.80	%		141.43	%		147.78	%		123.81	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 85/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Mid Cap Growth Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			From 5/28/15 (commencement of operations) to 10/31/15 (i)
Net asset value, beginning of period	$	10.24		$	10.67		$	11.70
Income from Investment Operations:
Net investment loss (ii)		(0.04	)		0.04			(0.02	)
Net realized and unrealized loss on investments		3.36			(0.47	)		(1.01	)
Total from investment operations		3.32			(0.43	)		(1.03	)
Net asset value, end of period	$	13.56		$	10.24		$	10.67
Total return (iii)		32.52	%		(4.03	)%		(8.80	)%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	13,306		$	7,508		$	2,413
Ratio of gross expenses to average net assets		1.07	%		1.23	%		1.76	%
Ratio of expense reimbursements to average net assets		(0.02	)%		(0.21	)%		(0.77	)%
Ratio of net expenses to average net assets		1.05	%		1.02	%		0.99	%
Ratio of net investment income (loss) to average net assets		(0.29	)%		0.40	%		(0.49	)%
Portfolio turnover rate		162.65	%		99.42	%		122.05	%

(i) Ratios have been annualized; total return has not been annualized; portfolio turnover is for the twelve months then ended.

(ii) Amount was computed based on average shares outstanding during the period.

(iii) Does not reflect the effect of sales charges, if applicable.

Prospectus 86/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger SMid Cap Focus Fund Class I

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	10.84		$	16.91		$	19.54		$	21.09		$	16.88
Income from Investment Operations:
Net investment loss (i)		(0.11	)		(0.07	)		(0.11	)		(0.09	)		(0.04	)
Net realized and unrealized gain on investments		3.64			(0.04	)		0.05			1.55			4.97
Total from investment operations		3.53			(0.11	)		(0.06	)		1.46			4.93
Distributions from net realized gains		(1.23	)		(5.96	)		(2.57	)		(3.01	)		(0.72	)
Net asset value, end of period	$	13.14		$	10.84		$	16.91		$	19.54		$	21.09
Total return (ii)		35.63	%		(0.79	)%		(0.48	)%		7.70	%		30.34	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	23,374		$	32,606		$	70,677		$	699,237		$	692,445
Ratio of gross expenses to average net assets		1.35	%		1.25	%		1.31	%		1.27	%		1.31	%
Ratio of expense reimbursements to average net assets		—			—			—			—			—
Ratio of net expenses to average net assets		1.35	%		1.25	%		1.31	%		1.27	%		1.31	%
Ratio of net investment income (loss) to average net assets		(0.99	)%		(0.58	)%		(0.62	)%		(0.45	)%		(0.22	)%
Portfolio turnover rate		157.39	%		164.36	%		110.40	%		91.59	%		95.67	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 87/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger SMid Cap Focus Fund Class Y

	From 8/31/17 (commencement of operations) to 10/31/17 (i)
Net asset value, beginning of period	$	12.27
Income from Investment Operations:
Net investment loss (ii)		(0.02	)
Net realized and unrealized gain on investments		0.89
Total from investment operations		0.87
Net asset value, end of period	$	13.14
Total return (iii)		7.09	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	107
Ratio of gross expenses to average net assets		9.54	%
Ratio of expense reimbursements to average net assets		(8.67	)%
Ratio of net expenses to average net assets		0.87	%
Ratio of net investment income (loss) to average net assets		(0.78	)%
Portfolio turnover rate		157.39	%

(i) Ratios have been annualized; total return has not been annualized; portfolio turnover is for the twelve months then ended.

(ii) Amount was computed based on average shares outstanding during the period.

(iii) Does not reflect the effect of sales charges, if applicable.

Prospectus 88/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger SMid Cap Focus Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	11.04		$	17.08		$	19.63		$	21.11		$	16.84
Income from Investment Operations:
Net investment income (loss) (i)		(0.09	)		(0.05	)		(0.06	)		(0.02	)		0.02
Net realized and unrealized gain (loss) on investments		3.74			(0.03	)		0.08			1.55			4.97
Total from investment operations		3.65			(0.08	)		0.02			1.53			4.99
Distributions from net realized gains		(1.23	)		(5.96	)		(2.57	)		(3.01	)		(0.72	)
Net asset value, end of period	$	13.46		$	11.04		$	17.08		$	19.63		$	21.11
Total return (ii)		36.11	%		(0.57	)%		(0.02	)%		8.07	%		30.78	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	52,736		$	29,565		$	134,051		$	52,091		$	67,852
Ratio of gross expenses to average net assets		1.06	%		1.01	%		0.99	%		0.95	%		0.96	%
Ratio of expense reimbursements to average net assets		—			—			—			—			—
Ratio of net expenses to average net assets		1.06	%		1.01	%		0.99	%		0.95	%		0.96	%
Ratio of net investment income (loss) to average net assets		(0.77	)%		(0.40	)%		(0.33	)%		(0.13	)%		0.13	%
Portfolio turnover rate		157.39	%		164.36	%		110.40	%		91.59	%		95.67	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 89/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Small Cap Growth Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	6.27		$	8.10		$	9.04		$	10.01		$	7.79
Income from Investment Operations:
Net investment loss (i)		(0.04	)		(0.03	)		(0.05	)		(0.04	)		(0.02	)
Net realized and unrealized gain (loss) on investments		2.37			(0.21	)		0.10			0.20			2.55
Total from investment operations		2.33			(0.24	)		0.05			0.16			2.53
Distributions from net realized gains		—			(1.59	)		(0.99	)		(1.13	)		(0.31	)
Net asset value, end of period	$	8.60		$	6.27		$	8.10		$	9.04		$	10.01
Total return (ii)		37.16	%		(3.55	)%		0.52	%		1.73	%		33.67	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	26,953		$	21,357		$	22,002		$	64,684		$	79,723
Ratio of gross expenses to average net assets		1.08	%		1.06	%		1.04	%		1.03	%		1.05	%
Ratio of expense reimbursements to average net assets		(0.09	)%		(0.07	)%		(0.05	)%		(0.04	)%		(0.06	)%
Ratio of net expenses to average net assets		0.99	%		0.99	%		0.99	%		0.99	%		0.99	%
Ratio of net investment income (loss) to average net assets		(0.50	)%		(0.41	)%		(0.55	)%		(0.45	)%		(0.18	)%
Portfolio turnover rate		30.32	%		55.25	%		131.72	%		88.98	%		93.97	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 90/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Small Cap Focus Fund Class I

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	11.44		$	11.22		$	11.75		$	13.17		$	11.00
Income from Investment Operations:
Net investment loss (i)		(0.11	)		(0.09	)		(0.12	)		(0.08	)		(0.05	)
Net realized and unrealized gain (loss) on investments		3.95			0.31			0.57			0.61			3.59
Total from investment operations		3.84			0.22			0.45			0.53			3.54
Distributions from net realized gains		—			—			(0.98	)		(1.95	)		(1.37	)
Net asset value, end of period	$	15.28		$	11.44		$	11.22		$	11.75		$	13.17
Total return (ii)		33.57	%		1.96	%		4.07	%		4.50	%		36.31	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	109,146		$	75,648		$	40,924		$	2,359		$	2,034
Ratio of gross expenses to average net assets		1.21	%		1.32	%		1.56	%		2.19	%		2.43	%
Ratio of expense reimbursements to average net assets		(0.01	)%		(0.09	)%		(0.21	)%		(0.84	)%		(1.08	)%
Ratio of net expenses to average net assets		1.20	%		1.23	%		1.35	%		1.35	%		1.35	%
Ratio of net investment income (loss) to average net assets		(0.80	)%		(0.81	)%		(1.07	)%		(0.70	)%		(0.46	)%
Portfolio turnover rate		44.56	%		75.50	%		162.44	%		91.91	%		92.82	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 91/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Small Cap Focus Fund Class Y

	From 3/1/17 (commencement of operations) to 10/31/17 (i)
Net asset value, beginning of period	$	12.93
Income from Investment Operations:
Net investment loss (ii)		(0.08	)
Net realized and unrealized loss on investments		2.59
Total from investment operations		2.51
Net asset value, end of period	$	15.44
Total return (iii)		19.41	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	3,279
Ratio of gross expenses to average net assets		1.51	%
Ratio of expense reimbursements to average net assets		(0.61	)%
Ratio of net expenses to average net assets		0.90	%
Ratio of net investment income (loss) to average net assets		(0.83	)%
Portfolio turnover rate		44.56	%

(i) Ratios have been annualized; total return has not been annualized; portfolio turnover is for the twelve months then ended.

(ii) Amount was computed based on average shares outstanding during the period.

(iii) Does not reflect the effect of sales charges, if applicable.

Prospectus 92/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Small Cap Focus Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	11.53		$	11.28		$	11.77		$	13.16		$	10.97
Income from Investment Operations:
Net investment loss (i)		(0.08	)		(0.07	)		(0.08	)		(0.05	)		(0.02	)
Net realized and unrealized gain (loss) on investments		3.99			0.32			0.57			0.61			3.58
Total from investment operations		3.91			0.25			0.49			0.56			3.56
Distributions from net realized gains		—			—			(0.98	)		(1.95	)		(1.37	)
Net asset value, end of period	$	15.44		$	11.53		$	11.28		$	11.77		$	13.16
Total return (ii)		33.91	%		2.22	%		4.43	%		4.78	%		36.61	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	350,097		$	68,253		$	17,109		$	3,368		$	3,202
Ratio of gross expenses to average net assets		0.90	%		1.01	%		1.56	%		2.11	%		2.38	%
Ratio of expense reimbursements to average net assets		—			—			(0.55	)%		(1.01	)%		(1.28	)%
Ratio of net expenses to average net assets		0.90	%		1.01	%		1.01	%		1.10	%		1.10	%
Ratio of net investment income (loss) to average net assets		(0.58	)%		(0.58	)%		(0.68	)%		(0.45	)%		(0.20	)%
Portfolio turnover rate		44.56	%		75.50	%		162.44	%		91.91	%		92.82	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 93/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Health Sciences Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			From 5/28/15 (commencement of operations) to 10/31/15 (i)
Net asset value, beginning of period	$	15.92		$	21.76		$	25.03
Income from Investment Operations:
Net investment loss (ii)		(0.11	)		(0.08	)		(0.05	)
Net realized and unrealized loss on investments		9.30			(2.37	)		(3.22	)
Total from investment operations		9.19			(2.45	)		(3.27	)
Distributions from net realized gains		—			(3.39	)		—
Net asset value, end of period	$	25.11		$	15.92		$	21.76
Total return (iii)		57.73	%		(13.63	)%		(13.06	)%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	25,644		$	4,980		$	6,517
Ratio of gross expenses to average net assets		1.12	%		1.16	%		1.36	%
Ratio of expense reimbursements to average net assets		(0.13	)%		(0.17	)%		(0.28	)%
Ratio of net expenses to average net assets		0.99	%		0.99	%		1.08	%
Ratio of net investment income (loss) to average net assets		(0.48	)%		(0.45	)%		(0.47	)%
Portfolio turnover rate		106.66	%		93.49	%		133.92	%

(i) Ratios have been annualized; total return has not been annualized; portfolio turnover is for the twelve months then ended.

(ii) Amount was computed based on average shares outstanding during the period.

(iii) Does not reflect the effect of sales charges, if applicable.

Prospectus 94/95

The Alger Funds Financial Highlights for a share outstanding throughout the period

Alger Growth & Income Fund Class Z

	Year ended 10/31/17			Year ended 10/31/16			Year ended 10/31/15			Year ended 10/31/14			Year ended 10/31/13
Net asset value, beginning of period	$	32.69		$	33.39		$	33.57		$	29.64		$	24.43
Income from Investment Operations:
Net investment income (i)		0.65			0.67			0.66			0.63			0.59
Net realized and unrealized gain on investments		6.99			0.26			0.82			4.00			5.14
Total from investment operations		7.64			0.93			1.48			4.63			5.73
Dividends from net investment income		(0.61	)		(0.59	)		(0.58	)		(0.70	)		(0.52	)
Distributions from net realized gains		(0.01	)		(1.04	)		(1.08	)
Net asset value, end of period	$	39.71		$	32.69		$	33.39		$	33.57		$	29.64
Total return (ii)		23.55	%		2.91	%		4.53	%		15.78	%		23.74	%
Ratios/Supplemental Data:
Net assets, end of period (000's omitted)	$	22,487		$	11,422		$	8,752		$	8,441		$	2,306
Ratio of gross expenses to average net assets		0.90	%		0.87	%		0.91	%		1.05	%		1.36	%
Ratio of expense reimbursements to average net assets		—			—			—			(0.10	)%		(0.41	)%
Ratio of net expenses to average net assets		0.90	%		0.87	%		0.91	%		0.95	%		0.95	%
Ratio of net investment income (loss) to average net assets		1.75	%		2.09	%		1.99	%		1.98	%		2.18	%
Portfolio turnover rate		7.78	%		5.36	%		15.83	%		21.20	%		29.27	%

(i) Amount was computed based on average shares outstanding during the period.

(ii) Does not reflect the effect of sales charges, if applicable.

Prospectus 95/95

Shareholder Information

Distributor

Fred Alger & Company, Incorporated
360 Park Avenue South
New York, NY 10010

Transfer Agent

DST Asset Manager Solutions, Inc.
P.O. Box 8480
Boston, MA 02266-8480

Net Asset Value

The value of one share is its "net asset value," or NAV. The NAV for a Fund is calculated as of the close of business (normally 4:00 p.m. Eastern time) every day the New York Stock Exchange ("NYSE") is open. Generally, the NYSE is closed on weekends and national holidays.

NAV (net asset value) of a class of shares is computed by adding together the value allocable to the class of the Fund's investments plus cash and other assets, subtracting applicable liabilities and then dividing the result by the number of outstanding shares of the class.

Foreign securities are usually valued on the basis of the most recent closing price of the foreign markets on which such securities principally trade. For each Fund, that invests in foreign securities principally listed on foreign exchanges that may trade on days the NYSE is closed the value of the Fund's assets may be affected on days when shareholders will not be able to purchase or redeem Fund shares.

The assets of each Fund are generally valued on the basis of market quotations. If market quotations are not readily available or do not accurately reflect fair value for a security, or if a security's value has been materially affected by events occurring after the close of the market on which the security is principally traded, the security may be valued on the basis of fair value as determined by the Manager under procedures adopted by the Trust's Board of Trustees. A security's valuation may differ depending on the method used for determining value. Short-term money market instruments held by the Funds are generally valued on the basis of amortized cost.

In determining whether market quotations are reliable and readily available, the Manager monitors information it routinely receives for significant events it believes will affect market prices of portfolio instruments held by a Fund. Significant events may affect a particular company (for example, a trading halt in the company's securities on

Prospectus A-1/A-11

an exchange during the day) or may affect securities markets (for example, a natural disaster that causes a market to close). If the Manager is aware of a significant event that has occurred after the close of the market where a portfolio instrument is primarily traded, but before the close of the NYSE, that the Manager believes has affected or is likely to affect the price of the instrument, the Manager will use its best judgment to determine a fair value for that portfolio instrument under procedures adopted by the Board of Trustees.

The Manager believes that under certain circumstances foreign securities values may be affected by volatility that occurs in U.S. markets on a trading day after the close of foreign securities markets. The Manager's fair valuation procedures therefore include a procedure whereby foreign securities prices may be "fair valued" to take those factors into account.

Dividends and Distributions and Tax Consequences

Except as noted below, all Funds declare and pay dividends and distributions annually. These Funds expect that the annual payments to shareholders will consist primarily of capital gains, which may be taxable to you at different rates depending upon how long the Fund held the securities that it sold to create the gains (rather than the length of time you have held shares of the Fund), and that they will also include net investment income, which is taxable as ordinary income. Certain dividend income received by a Fund and paid to you may be subject to a maximum tax rate of 20% (qualified dividends); other income paid to you, such as non-qualifying dividend income or interest earned on debt securities held by the Fund, will continue to be taxed at the higher ordinary income rates. Participants in tax-deferred accounts ordinarily will not be subject to taxation on dividends from net investment income and net realized capital gains until they receive a distribution of the dividends from their individual plan accounts. Dividends and distributions may differ among classes of shares of a Fund.

Alger Growth & Income Fund declares and pays dividends from net investment income quarterly. Distributions from net realized gains are declared and paid annually after the end of the fiscal year in which they were earned.

Unless you choose to receive cash payments by checking the box on your account application, any dividends and distributions will be reinvested automatically at the NAV on their payment dates. No sales charge will apply to automatically reinvested dividends and distributions. If you have chosen cash payments and a payment is returned to the Fund as undeliverable, that payment will be reinvested upon receipt by the Transfer Agent in Fund shares at the next NAV. All subsequent payments will be reinvested until you reinstate your cash election and provide a valid mailing address.

Prospectus A-2/A-11

Regardless of whether you choose to take distributions in cash or reinvest them in the Fund, they may be subject to federal and state taxes. An exchange of Fund shares for shares of another fund will be treated as a sale of the Fund shares, and any gain on the transaction may be subject to federal and state taxes. Because everyone's tax situation is unique, see a tax advisor about federal, state and local tax consequences of investing in the Funds.

Classes of Fund Shares

Each of Alger Capital Appreciation Fund, Alger Mid Cap Growth Fund, and Alger Small Cap Growth Fund offers four classes of shares (Class A, B, C and Z Shares). Each of Alger Health Sciences Fund and Alger Growth & Income Fund offers three classes of shares (Class A, C and Z Shares). Each of Alger Small Cap Focus Fund and Alger SMid Cap Focus Fund offers five classes of shares (A, C, I, Y, and Z Shares). Class I, Y and Z Shares are offered by this Prospectus. Class A, B and C Shares, which are offered in a separate prospectus, are each subject to a sales charge. Class I, and Z Shares are generally offered only to institutional investors, including, but not limited to, qualified pension and retirement plans. Class I Shares are subject to Distribution and/or Shareholder Servicing Fees of 0.25%. Class Y Shares and Class Z Shares have no Distribution or Shareholder Servicing Fees.

Purchasing and Redeeming Fund Shares

Class I Shares are available to institutional investors, such as corporations, foundations, and trusts managing various types of employee benefit plans, as well as charitable, religious and educational institutions. Typical institutional investors include banks, insurance companies, broker-dealers, investment advisers, investment companies, qualified pension and profit-sharing plans, non-qualified deferred compensation plans, trusts funding charitable, religious and educational institutions and investors who invest through such institutions (or through an organization that processes investor orders on behalf of such institutions) and do so by paying a management, consulting or other fee to such institutions for the right to invest.

Class Y Shares are available for purchase by institutional investors such as qualified and non-qualified retirement, deferred compensation, and benefit plans, bank and trust companies, insurance companies, corporations, charitable organizations, endowments and foundations, government entities, and fund-of-funds. Class Y Shares are generally subject to a minimum initial investment and a minimum account size requirement of $500,000.

The Fund's Class Z Shares, which are generally subject to a minimum initial investment of $500,000, provide an investment vehicle for qualified or non-qualified retirement or employment benefit plans; banks, bank trust departments and trust companies; Section 529 college savings plans; asset-based fee programs; fee-paying clients of a registered investment advisor; corporations; insurance companies; registered investment companies; foundations and endowments; charitable, religious and educational institutions; and individual investors.

Prospectus A-3/A-11

There is no maximum investment limit for Class I, Y or Z Shares.

The Distributor may waive the minimum initial investment of $500,000 for Class Z Shares of the Funds for group employer-sponsored 401(k) plans, 457 plans, employer sponsored 403(b) plans, profit-sharing and money purchase pension plans, defined benefit plans, retiree health benefit plans and non-qualified deferred compensation plans. The waiver is available only for retirement plans that hold omnibus positions, or for aggregate plan participant positions, for each Fund made available for the plan. The waiver is generally not available to non-retirement accounts, traditional and Roth Individual Retirement Accounts, Coverdell Education Savings Accounts, SEPs, SARSEPs, SIMPLE IRAs, individual 401(k) plans or individual 403(b) plans. As the Distributor has no information regarding the nature of the underlying shareholders in an omnibus account (in which shares are held in the name of an intermediary on behalf of multiple beneficial owners, a common form of holding shares among retirement plans and financial intermediaries such as brokers, advisers and third-party administrators) it cannot aid in the substantiation of any such claims for a waiver of the minimum initial investment.

Additional Information about Minimum Initial Investments

The Distributor, in its sole discretion, may waive minimum initial investment requirements. Minimum initial investment and related requirements may be modified at any time, without prior notice.

There is no minimum initial investment for the following categories of eligible investors:

• Any current employee of Fred Alger Management, Inc. or Fred Alger & Company, Incorporated, or their affiliates, and any of their immediate family members who share the same address.

• Trustees of the Funds and Directors of Alger Associates, Inc., or its affiliates, and any of their immediate family members who share the same address.

Class Y, and Z investment minimums are waived for the following:

• Certain types of fee based programs and group retirement accounts (e.g., 401(k) plans or employer-sponsored 403(b) plans);

• Omnibus group retirement accounts;

• Financial intermediaries who have entered into an agreement with the Distributor to offer shares through a wrap and/or asset allocation program;

• Financial intermediaries who have entered into an agreement with the Distributor to offer shares through a no-load network or platform, or through a self-directed investment brokerage account program that charges a transaction fee to its clients;

• Certain financial institutions and third-party recordkeepers and/or administrators who have agreements with the Distributor with respect to such purchases, and who

Prospectus A-4/A-11

buy shares for their accounts on behalf of investors in retirement plans and deferred compensation plans;

• Registered investment advisors clearing through multiple firms having an aggregate $1,000,000 or more invested in Alger Fund shares.

Shares of a Fund can be purchased or redeemed on any day the NYSE is open. Orders will be processed at the NAV next calculated after the purchase or redemption request is received in good order by the Transfer Agent or other agent appointed by the Distributor. Ordinarily, the Fund will issue a redemption check within seven days after the Transfer Agent receives a redemption request in good order. "In good order" means that all necessary information and documentation related to the redemption request have been provided to the Fund's transfer agent or authorized intermediary, if applicable. If your request is not in good order, the Fund's transfer agent may require additional documentation in order to redeem your shares. Payment may be postponed in cases where the SEC declares an emergency or normal trading is halted. The Transfer Agent or the Fund may reject any purchase order. Share certificates are not issued for shares of the Fund.

Under normal circumstances, each Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio and/or by selling portfolio assets to generate cash. A Fund also may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time.

Each Fund may pay all or a portion of your redemption proceeds in securities rather than cash (i.e., "redeem in kind") if, for example, the redemption request is during stressed market conditions or the Fund believes that a cash redemption may have a substantial impact on the Fund and its remaining shareholders. Securities will generally be selected on a pro rata basis pursuant to the Fund's procedures. A shareholder who receives a redemption in kind bears the market risk of the securities until they are converted into cash, in transactions conducted at the shareholder's expense.

Legislation passed by Congress in 2008 requires mutual funds to report both to the shareholder and to the Internal Revenue Service the "cost basis" of shares acquired on or after January 1, 2012 that are subsequently redeemed or exchanged. This reporting is not required for Fund shares held in retirement or other tax-advantaged accounts or for certain other types of entities (such as C corporations).

If you are a direct shareholder, you may request your cost basis reported on Form 1099-B to be calculated using any one of the alternative methods offered by the Fund. Please contact the Fund to make, revoke, or change your election. If you do not affirmatively elect a cost basis method then the Fund will use the average cost basis method. If you hold Fund shares through a broker, please contact that broker with respect to the reporting of cost basis and available elections for your account.

Please note that you will continue to be responsible for calculating and reporting gains and losses on redemptions of shares purchased prior to January 1, 2012. You

Prospectus A-5/A-11

are encouraged to consult your tax advisor regarding the application of the cost basis reporting rules and, in particular, which cost basis calculation method is best for you.

Exchanges

You can exchange shares of a Fund for shares of another Fund, subject to certain restrictions. Shares of the Funds can be exchanged or redeemed via telephone under certain circumstances. The Funds and Transfer Agent have reasonable procedures in place to determine that telephone instructions are genuine. They include requesting personal identification and recording calls. If the Funds and Transfer Agent follow these procedures, they are not liable for acting in good faith on telephone instructions. For more information on telephone exchanges and redemptions, contact the Transfer Agent.

Other Purchase and Exchange Limitations

If you are a participant in a retirement plan, such as a 401(k) plan, and you purchase shares in the Funds through an administrator or trustee that maintains a master or "omnibus" account with one or more Funds for trading on behalf of retirement plans and their participants, the Administrator may apply purchase and exchange limitations which are different than the limitations discussed herein. These limitations may be more or less restrictive than the limitations imposed by the Funds. Consult with your Administrator to determine what purchase and exchange limitations may be applicable to your transactions in the Funds through your retirement plan.

Limitations on Excessive Trading

Each of the Funds, except for International Fund, invests predominantly in U.S.-traded, highly liquid securities for which current New York Stock Exchange closing prices are readily available on a daily basis. Each Fund will determine a fair value for portfolio securities for which current market closing prices are not readily available or otherwise require fair valuation in the circumstances discussed under "Net Asset Value." Active trading may be attempted and may, if carried out on a large scale, impose burdens on the Funds' portfolio managers, interfere with the efficient management of a Fund, increase the Fund's transaction costs, administrative costs or tax liability or otherwise be detrimental to the interests of the Fund and its other shareholders. The Funds therefore discourage market timing, and to the extent possible monitor for market timing patterns in each of the Funds.

The Board of Trustees has adopted policies and procedures to discourage frequent and/or short-term trading of Fund shares. These policies and procedures allow a Fund to reject purchase or exchange orders, on a temporary or permanent basis, or redeem all Fund shares from investors that the Manager believes, in its reasonable business judgment, are engaging in frequent and/or short-term trading in Fund shares or shares of other funds sponsored by the Manager that is detrimental to the Fund involved. If the Fund rejects your purchase or exchange order, you will not be

Prospectus A-6/A-11

able to execute that transaction, and neither the Fund nor the Manager will be responsible for any losses you may suffer as a result.

In order to detect significant market timing, the Manager, in accordance with policies and procedures approved by the Trustees, will, among other things, seek to monitor overall subscription, redemption and exchange activity, and isolate significant daily activity to determine if there appears to be market timing activity in an individual portfolio. The Funds might not be able to detect frequent or short-term trading conducted by the underlying owners of shares held in omnibus accounts (in which shares are held in the name of an intermediary on behalf of multiple beneficial owners, a common form of holding shares among retirement plans and financial intermediaries such as brokers, advisers and third-party administrators) or placed through market intermediaries other than on a fully-disclosed basis, and therefore might not be able to effectively prevent frequent or short-term trading in those accounts. The Manager attempts to monitor these activities in omnibus accounts and will contract with broker-dealers that sell shares of the Funds and entities that hold omnibus accounts with its mutual funds to seek to discourage, detect and prevent market timing and active trading. For these and other reasons, there is no guarantee that the Funds' efforts to identify investors who engage in excessive trading activity or to curtail that activity will be successful.

Disclosure of Portfolio Holdings

The Board of Trustees has adopted policies and procedures relating to disclosure of the Funds' portfolio securities. These policies and procedures recognize that there may be legitimate business reasons for holdings to be disclosed and seek to balance those interests to protect the proprietary nature of the trading strategies and implementation thereof by the Funds.

Generally, the policies prohibit the release of information concerning portfolio holdings which have not previously been made public to individual investors, institutional investors, intermediaries that distribute the Funds' shares and other parties which are not employed by the Manager or its affiliates except when the legitimate business purposes for selective disclosure and other conditions (designed to protect the Funds) are acceptable.

The Funds make their full holdings available semi-annually in shareholder reports filed on Form N-CSR and after the first and third fiscal quarters in regulatory filings on Form N-Q. These shareholder reports and regulatory filings are filed with the SEC, as required by federal securities laws, and are generally available within sixty (60) days of the end of the Funds' fiscal quarter.

In addition, the Funds make publicly available their respective month-end top 10 holdings with a 10 day lag and their month-end full portfolios with a 60 day lag on their website www.alger.com and through other marketing communications (including printed advertising/sales literature and/or shareholder telephone customer serv-

Prospectus A-7/A-11

ice centers). No compensation or other consideration is received for the non-public disclosure of portfolio holdings information.

In accordance with the foregoing, the Funds provide portfolio holdings information to third parties including financial intermediaries and service providers who need access to this information in the performance of their services and are subject to duties of confidentiality (1) imposed by law, including a duty not to trade on non-public information, and/or (2) pursuant to an agreement that confidential information is not to be disclosed or used (including trading on such information) other than as required by law. This agreement must be approved by the Funds' Chief Compliance Officer, President, Secretary or Assistant Secretary.

The Board of Trustees periodically reviews a report disclosing the third parties to whom each Fund's holdings information has been disclosed and the purpose for such disclosure, and it considers whether or not the release of information to such third parties is in the best interest of the Fund and its shareholders.

In addition to material the Funds routinely provide to shareholders, the Manager may, upon request, make additional statistical information available regarding the Alger Family of Funds. Such information will include, but not be limited to, relative weightings and characteristics of a Fund portfolios versus its peers or an index (such as P/E (or price to book) ratio, EPS forecasts, alpha, beta, capture ratio, maximum drawdown, standard deviation, Sharpe ratio, information ratio, R-squared, and market cap analysis), security specific impact on overall portfolio performance, return on equity statistics, geographic analysis, number of holdings, month-end top ten contributors to and detractors from performance, breakdown of High Unit Volume Growth holdings vs. Positive Lifecycle Change holdings, portfolio turnover, and requests of a similar nature. Please contact the Funds at (800) 992-3863 to obtain such information.

Other Information

A Fund may redeem some of your shares "in kind," which means that some of the proceeds will be paid with securities the Fund owns instead of cash. If you receive securities, you should expect to incur brokerage or other charges in converting the securities to cash. If a Fund pays large redemptions in cash, these transactions may increase the Fund's transaction costs and detract from the Fund's performance. Large purchases pose similar risks.

Shares may be worth more or less when you redeem them than they were at the time you bought them. For tax purposes, this means that when you redeem them you may realize a short- or long-term capital gain or loss, depending upon how long you have held the shares.

Each Fund may pay the Distributor, Fred Alger & Company, Incorporated, or other entities, a fee of up to 0.25% of the value of the Fund's average daily net assets for ongoing service and/or maintenance of shareholder accounts with respect to Class I

Prospectus A-8/A-11

and Class R Shares. This fee is included in the Fund's shareholder servicing fee. The Distributor may pay some or all of this fee to a broker-dealer, investment adviser or other financial institution ("Financial Intermediary") that also provides servicing and/or maintenance of shareholder accounts.

Other Payments by the Funds. In addition to fees that the Funds may pay to a Financial Intermediary pursuant to the Rule 12b-1 plan and fees the Funds pay to their transfer agent, DST Asset Manager Solutions, Inc., the Distributor, on behalf of a Fund, may enter into agreements with Financial Intermediaries pursuant to which a Fund will pay a Financial Intermediary for networking, sub-transfer agency and/or sub-accounting services. These payments are generally based on either (1) a percentage of the average daily net assets of Fund shareholders serviced by a Financial Intermediary or (2) a fixed dollar amount for each account serviced by a Financial Intermediary. The aggregate amount of these payments may be substantial.

Additional Compensation. From time to time the Distributor, at its expense from its own resources, may compensate Financial Intermediaries who are instrumental in effecting investments by their clients or customers in a Fund, in an amount up to 1% of the value of those investments. The Distributor may also from time to time, at its expense from its own resources, make payments to Financial Intermediaries that provide shareholder servicing, or transaction processing, with such payments structured as a percentage of gross sales, a percentage of net assets, and/or as a fixed dollar amount (the latter as a per account fee or as reimbursement for transactions processing and transmission charges). Payments under these other arrangements may vary but generally will not exceed 0.50% annually of the value of the Fund's assets or 0.50% annually of the value of the Fund's sales attributable to that Financial Intermediary. The Distributor determines whether to make any additional cash payments and the amount of any such payments in response to request from Financial Intermediaries, based on factors the Distributor deems relevant. Factors considered by the Distributor generally include the Financial Intermediary's reputation, ability to attract and retain assets for the Fund, expertise in distributing a particular class of shares of a Fund, entry into target markets, and/or quality of service. In addition, the Distributor may make payments to dealer firms in the form of payments for marketing support, seminar support, training meetings, or comparable expenses in the discretion of the Distributor. Please contact your Financial Intermediary for details about revenue sharing payments it may receive. Any payments described above will not change the price paid by investors for the purchase of shares of a Fund or the amount of proceeds received by a Fund on the sale of shares.

Redemptions by the Funds. If your account has been open at least one year, you have not made an additional purchase in the account during the past six calendar months, and the value of your account falls below the minimum initial investment amount for three consecutive months as a result of redemptions or exchanges (excluding Trust-sponsored retirement accounts), the Fund may redeem all your Fund shares within your account after giving you 60 days' prior written notice. You may

Prospectus A-9/A-11

avoid having your account redeemed during the notice period by bringing the account value up to the minimum initial investment amount.

Each Fund and its agents reserve the right at any time to: reject or cancel all or any part of any purchase or exchange order (When an exchange request in respect of Fund shares is rejected, such shares may be redeemed from the Fund on request of the shareholder.); redeem all Fund shares; modify any terms or conditions of purchase of shares of any Fund; or suspend, change or withdraw all or any part of the offering made by this prospectus. If the Fund rejects your purchase or exchange order, you may not be able to execute that transaction, and the Fund and its agents will not be responsible for any losses you may suffer as a result.

Lost Shareholders, Inactive Accounts and Unclaimed Property. It is important that each Fund maintain a correct address for each shareholder. An incorrect address may cause a shareholder's account statements and other mailings to be returned to a Fund. Based upon statutory requirements for returned mail, the Fund will attempt to locate the shareholder or rightful owner of the account. If the Fund is unable to locate the shareholder, then it will determine whether the shareholder's account can legally be considered abandoned. Your mutual fund account may be transferred to the state government of your state of residence if no activity occurs within your account during the "inactivity period" specified in your state's abandoned property laws. Each Fund is legally obligated to escheat (or transfer) abandoned property to the appropriate state's unclaimed property administrator in accordance with statutory requirements. The shareholder's last known address of record determines which state has jurisdiction. If you hold your account directly at the Transfer Agent, please proactively contact the Transfer Agent toll-free at (800) 992-3863 at least annually to ensure your account remains in active status.

If you are a resident of the state of Texas, you may designate a representative to receive notifications that, due to inactivity, your mutual fund account assets may be delivered to the Texas Comptroller. Please contact the Transfer Agent if you wish to complete a Texas Designation of Representative form.

Prospectus A-10/A-11

For Fund Information:

By Telephone: (800) 992-3362

By Mail: DST Asset Manager Solutions, Inc.
Attn: The Alger Funds
P.O. Box 8480
Boston, MA 02260-8480

Statement of Additional Information

For more detailed information about each Fund and its policies, please read the Funds' Statement of Additional Information, which is incorporated by reference into (is legally made a part of) its Prospectus. You can get a free copy of the Statement of Additional Information by calling the Funds' toll-free number, at the Funds' website at http://www.alger.com or by writing to the address above. The Statement of Additional Information is on file with the SEC.

Annual and Semi-Annual Reports

Additional information about the Funds' investments is available in the Funds' annual and semi-annual reports to shareholders. In the Funds' annual report you will find a discussion of the market conditions and investment strategies that significantly affected the Funds' performance during the period covered by the report. You can receive free copies of these reports by calling the Funds' toll-free number, at the Fund's website at http://www.alger.com or by writing to the address above.

Another way you can review and copy Fund documents is by visiting the SEC's Public Reference Room in Washington, DC. Copies can also be obtained, for a duplicating fee, by e-mail request to publicinfo@sec.gov or by writing to the SEC's Public Reference Section, Washington, DC 20549-1520. Information on the operation of the Public Reference Room is available by calling (202) 551-8090. Fund documents are also available on the EDGARdatabase on the SEC's Internet site at http://www.sec.gov.

Quarterly Fund Holdings

Each Fund's most recent month-end portfolio holdings are available approximately sixty days after month-end on the Fund's website at www.alger.com. Each Fund also files its complete schedule of portfolio holdings with the SEC for the first and third quarter of each fiscal year on Form N-Q. Forms N-Q are available online on the SEC's website at http://www.sec.gov. The Funds' Forms N-Q may be reviewed and copied at the SEC's Public Reference Room in Washington, D.C. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling (202) 551-8090. A copy of the most recent quarterly holdings may also be obtained from the Funds by calling (800) 992-3362.

Distributor: Fred Alger & Company, Incorporated

The Alger Funds SEC File #811-1355

TAF-Instl.

Prospectus A-11/A-11