Lord Abbett Alpha Strategy Fund

Lord Abbett Alpha Strategy Fund

INVESTMENT OBJECTIVE

The Fund’s investment objective is long-term capital appreciation.

FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and certain members of your family invest, or agree to invest in the future, at least $50,000 in the Lord Abbett Family of Funds. More information about these and other discounts is available from your financial professional and in “Sales Charge Reductions and Waivers” on page 185 of the prospectus, Appendix A to the prospectus, titled “Intermediary-Specific Sales Charge Reductions and Waivers,” and “Purchases, Redemptions, Pricing, and Payments to Dealers” on page 8-1 of the statement of additional information (“SAI”).

Shareholder Fees (Fees paid directly from your investment)

Shareholder Fees - Lord Abbett Alpha Strategy Fund	Class A		Class B	Class C		Class F	Class F3	Class I	Class P	Class R2	Class R3	Class R4	Class R5	Class R6	Class T
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.75%		none	none		none	none	none	none	none	none	none	none	none	2.50%
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)	none	[1]	5.00%	1.00%	[2]	none	none	none	none	none	none	none	none	none	none

Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Lord Abbett Alpha Strategy Fund		Class A	Class B	Class C	Class F	Class F3		Class I	Class P	Class R2	Class R3	Class R4	Class R5	Class R6	Class T
Management Fees	[1]	0.10%	0.10%	0.10%	0.10%	0.10%		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and Service (12b-1) Fees		0.25%	1.00%	1.00%	0.10%	none		none	0.45%	0.60%	0.50%	0.25%	none	none	0.25%
Other Expenses		0.22%	0.22%	0.22%	0.22%	0.09%	[2]	0.22%	0.22%	0.22%	0.22%	0.22%	0.22%	0.09%	0.22%	[2]
Acquired Fund Fees and Expenses		1.06%	1.06%	1.06%	1.06%	1.06%	[2]	1.06%	1.06%	1.06%	1.06%	1.06%	1.06%	1.06%	1.06%	[2]
Total Annual Fund Operating Expenses		1.63%	2.38%	2.38%	1.48%	1.25%	[2]	1.38%	1.83%	1.98%	1.88%	1.63%	1.38%	1.25%	1.63%	[2]

Example

This 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 and then redeem all of your shares at the end of those periods. The Example also assumes 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 your costs would be:

If Shares Are Redeemed

Expense Example - Lord Abbett Alpha Strategy Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Class A	731	1,060	1,411	2,397
Class B	741	1,042	1,470	2,530
Class C	341	742	1,270	2,716
Class F	151	468	808	1,768
Class F3	127	397	686	1,511
Class I	140	437	755	1,657
Class P	186	576	990	2,148
Class R2	201	621	1,068	2,306
Class R3	191	591	1,016	2,201
Class R4	166	514	887	1,933
Class R5	140	437	755	1,657
Class R6	127	397	686	1,511
Class T	412	751	1,114	2,134

If Shares Are Not Redeemed

Expense Example No Redemption - Lord Abbett Alpha Strategy Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Class A	731	1,060	1,411	2,397
Class B	241	742	1,270	2,530
Class C	241	742	1,270	2,716
Class F	151	468	808	1,768
Class F3	127	397	686	1,511
Class I	140	437	755	1,657
Class P	186	576	990	2,148
Class R2	201	621	1,068	2,306
Class R3	191	591	1,016	2,201
Class R4	166	514	887	1,933
Class R5	140	437	755	1,657
Class R6	127	397	686	1,511
Class T	412	751	1,114	2,134

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 the 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 12.50% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Fund is a “fund of funds” that invests principally in affiliated mutual funds managed by Lord, Abbett & Co. LLC (the “underlying funds”). Under normal conditions, through the underlying funds, the Fund indirectly invests principally in the equity securities of U.S. and foreign micro-cap, small, and mid-sized companies. The Fund uses a “blend” strategy to gain investment exposure to both growth and value stocks, or to stocks with characteristics of both. Through the underlying funds, the Fund’s assets are allocated primarily to the following types of investments:

• Equity securities of micro-cap, small, and mid-sized companies. The underlying funds may invest in any security that represents equity ownership in a company. Equity securities in which the Fund may invest include common stocks, preferred stocks, equity interests in trusts (including real estate investment trusts (“REITs”) and privately offered trusts), partnerships, joint ventures, limited liability companies and vehicles with similar legal structures, and other instruments with similar characteristics. The underlying funds consider equity securities to include rights offerings and investments that convert into the equity securities described above.

• Growth companies that the underlying funds believe exhibit faster-than-average gains in earnings and have the potential to continue profit growth at a high level.

• Value companies that the underlying funds believe to be undervalued according to certain financial measurements of intrinsic worth or business prospects and to have the potential for capital appreciation.

• Foreign securities, including emerging market securities and American Depositary Receipts (“ADRs”). The Fund defines foreign companies as those whose securities are traded primarily on non-U.S. securities exchanges. Because ADRs represent exposure to foreign companies, the Fund deems them to be foreign investments even though they trade on U.S. exchanges. Foreign securities may be denominated in the U.S. dollar or other currencies.

In addition to investing in the underlying funds, the Fund may invest directly in any type of derivative as part of its investment strategies or for risk management purposes. Currently, the Fund invests in derivatives consisting principally of futures, forwards, options, and swaps. To the extent the Fund invests in derivatives, the Fund intends to do so primarily for non-hedging purposes. When investing in this manner, the Fund may use a derivative investment, such as an index future, to adjust exposure to, or to change the weighting of its investments in, a particular asset class without increasing or decreasing the allocation among the underlying funds. The Fund may use derivatives to gain exposure to any asset class, whether or not represented by the underlying funds. The Fund also may sell index futures short to reduce its exposure to a particular asset class represented by the index or to profit from an anticipated decline in the returns of the index. The aggregate notional value of the Fund’s directly held positions in derivatives, determined at the time of the most recent position established, will not exceed 50% of the Fund’s net assets. The Fund currently expects, however, that the aggregate notional value of such instruments, determined at the time of the most recent position established, will not exceed 35% of the Fund’s net assets under normal conditions. These percentage limitations exclude Fund assets indirectly invested in derivatives through the underlying funds.

The portfolio management team allocates the Fund’s assets among underlying funds that invest in equity securities across micro, small and mid-sized market capitalization ranges and all investment styles, and that invest in select non-U.S. companies. The portfolio management team generally employs a bottom-up investment approach emphasizing long term value.

The Fund generally will sell and reallocate its investments away from particular underlying funds when the Fund believes such a fund is less likely to benefit from the current market and economic environment, has a portfolio that shows signs of deteriorating fundamentals, or has reached its valuation target, among other reasons. The Fund seeks to remain fully invested in accordance with its investment objective; however, in response to adverse economic, market or other unfavorable conditions, the Fund may invest its assets in a temporary defensive manner.

PRINCIPAL RISKS

As with any investment in a mutual fund, investing in the Fund involves risk, including the risk that you may receive little or no return on your investment. When you redeem your shares, they may be worth more or less than what you paid for them, which means that you may lose a portion or all of the money you invested in the Fund. The principal risks of investing in the Fund also are the principal risks of investing in the underlying funds. These risks, which could adversely affect the Fund’s performance, include:

• Underlying Fund Risk: The assets of the Fund are invested principally in the underlying funds. As a result, the investment performance of the Fund is directly related to the investment performance of the underlying funds in which it invests. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds. The Fund typically will invest in a diversified portfolio of underlying funds; however, to the extent that the Fund invests a significant portion of its assets in a single underlying fund it may be more susceptible to risks associated with that fund and its investments. It is possible that the holdings of underlying funds may contain securities of the same issuers, thereby increasing the Fund’s exposure to such issuers. It also is possible that one underlying fund may be selling a particular security when another is buying it, producing little or no change in exposure but generating transaction costs and/or resulting in realization of gains with no economic benefit. There can be no assurance that the investment objective of any underlying fund will be achieved. Lord, Abbett & Co. LLC is the investment adviser for both the Fund and the underlying funds and may be deemed to have a conflict of interest in determining the allocation of the Fund’s assets among the various underlying funds. In addition, the Fund’s shareholders will indirectly bear their proportionate share of the underlying funds’ fees and expenses as well as their proportionate share of the Fund’s fees and expenses.

• Portfolio Management Risk: If the strategies used and investments selected by the Fund’s portfolio management team and/or the teams of the underlying funds fail to produce the intended results, the Fund and/or the underlying funds may not achieve their respective objectives. There can be no assurance that the allocation of Fund assets among the underlying funds or the Fund’s use of derivatives will maximize returns, minimize risks, or be appropriate for all investors. As a result, the Fund may suffer losses or underperform other funds with the same investment objective or strategies, even in a rising market.

• Market Risk: The market values of securities will fluctuate, sometimes sharply and unpredictably, based on overall economic conditions, governmental actions or intervention, political developments and other factors. Prices of equity securities tend to rise and fall more dramatically than those of debt securities.

• Equity Securities Risk: Equity securities, as well as equity-like securities such as convertible debt securities, may experience significant volatility. Such securities may fall sharply in response to adverse events affecting overall markets, a particular industry or sector, or an individual company’s financial condition.

• Industry and Sector Risk: Although the Fund does not employ an industry or sector focus, its exposure to specific industries or sectors will increase from time to time based on the portfolio management team’s perception of investment opportunities. If an underlying fund overweights a single industry or sector relative to its benchmark index, the underlying fund will face an increased risk that the value of its portfolio will decrease because of events disproportionately affecting that industry or sector. Furthermore, investments in particular industries or sectors may be more volatile than the broader market as a whole.

• Micro-Cap, Small, and Mid-Sized Company Risk: The equity securities of micro-cap, small, and mid-sized companies typically involve greater investment risks than larger, more established companies. As compared to larger companies, micro-cap, small, and mid-sized companies may have limited management experience or depth, limited ability to generate or borrow capital needed for growth, and limited products or services, or operate in less established markets. Accordingly, micro-cap, small, and mid-sized company securities tend to be more sensitive to changing economic, market, and industry conditions and tend to be more volatile and less liquid than equity securities of larger companies, especially over the short term. Micro-cap, small, and mid-sized companies also may fall out of favor relative to larger companies in certain market cycles, causing the Fund to incur losses or underperform. The shares of micro-cap, small, and mid-sized companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the ability to sell these securities in the future.

• Blend Style Risk: Growth stocks tend to be more volatile than slower-growing value stocks. Growth stocks typically trade at higher multiples of current earnings than other stocks. Growth stocks often are more sensitive to market fluctuations than other securities because their market prices are highly sensitive to future earnings expectations. At times when it appears that these expectations may not be met, growth stocks’ prices typically fall. The prices of value stocks may lag the stock market for long periods of time if the market fails to recognize the company’s intrinsic worth. Value investing also is subject to the risk that a company judged to be undervalued may actually be appropriately priced or even overpriced. A portfolio that combines growth and value styles may diversify these risks and lower its volatility, but there is no assurance this strategy will achieve that result.

• Foreign and Emerging Market Company Risk: Investments in foreign (including emerging market) companies and in U.S. companies with economic ties to foreign markets generally involve special risks that can increase the likelihood that the Fund will lose money. For example, as compared with companies organized and operated in the U.S., these companies may be more vulnerable to economic, political, and social instability and subject to less government supervision, lack of transparency, inadequate regulatory and accounting standards, and foreign taxes. In addition, the securities of foreign companies also may be subject to inadequate exchange control regulations, the imposition of economic sanctions or other government restrictions, higher transaction and other costs, reduced liquidity, and delays in settlement to the extent they are traded on non-U.S. exchanges or markets. Foreign company securities also include ADRs. ADRs may be less liquid than the underlying shares in their primary trading market. Foreign securities also may subject the Fund’s investments to changes in currency rates. Emerging market securities generally are more volatile than other foreign securities, and are subject to greater liquidity, regulatory, and political risks. Investments in emerging markets may be considered speculative and generally are riskier than investments in more developed markets because such markets tend to develop unevenly and may never fully develop. Emerging markets are more likely to experience hyperinflation and currency devaluations. Securities of emerging market companies may have far lower trading volumes and less liquidity than securities of issuers in developed markets. Companies with economic ties to emerging markets may be susceptible to the same risks as companies organized in emerging markets.

• Foreign Currency Risk: Certain of the underlying funds may invest in securities denominated in foreign (including emerging market) currencies, which are 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.

• Derivatives Risk: Derivatives can increase the Fund’s volatility and/or reduce the Fund’s returns. Derivatives are subject to certain risks, including the risk that the value of the derivative may not correlate with the value of the underlying asset, rate, or index in the manner anticipated by portfolio management. In addition, investments in many types of derivatives involve heightened counterparty, liquidity, leverage, and other risks. Counterparty risk is the risk that the other party in a transaction may fail to fulfill its contractual obligations, leaving the Fund or an underlying fund to bear the resulting losses. Central clearing of derivatives is intended to decrease counterparty risk but does not make these transactions risk-free. If there is no liquid secondary trading market for derivatives, the Fund or an underlying fund may be unable to sell or otherwise close a derivatives position, exposing it to losses and making it more difficult to value accurately any derivatives in its portfolio. Because derivatives involve a small initial investment relative to the risk assumed (known as leverage), derivatives can magnify the Fund’s or an underlying fund’s losses. Short selling derivatives the Fund does not own involves heightened leverage. This means that the Fund’s losses will be magnified if the Fund short sells index futures and the reference index later increases in value. In addition, the Fund will be required to segregate permissible liquid assets to cover its obligations under these transactions and may have to liquidate positions before it is desirable to do so to fulfill its requirements to segregate. Whether the Fund’s use of derivatives is successful will depend on, among other things, the Fund’s ability to correctly forecast market movements and other factors. If the Fund incorrectly forecasts these and other factors, the Fund’s performance could suffer.

• Liquidity/Redemption Risk: The Fund may lose money when selling securities at inopportune times to fulfill shareholder redemption requests. The risk of loss may increase depending on the size and frequency of redemption requests, whether the redemption requests occur in times of overall market turmoil or declining prices, and whether the securities the Fund intends to sell have decreased in value or are illiquid.

An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. For more information on the principal risks of the Fund, please see the “More Information About the Funds – Principal Risks” section in the prospectus.

PERFORMANCE

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund’s returns. Each assumes reinvestment of dividends and distributions. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. No performance is shown for Class P shares because the Fund has not issued Class P shares. No performance is shown for Class F3 or T shares because these classes have not completed a full calendar year of operations as of the date of this prospectus.

The bar chart shows changes in the performance of the Fund’s Class A shares from calendar year to calendar year. This chart does not reflect the sales charge applicable to Class A shares. If the sales charge were reflected, returns would be lower. Performance for the Fund’s other share classes will vary due to the different expenses each class bears. Updated performance information is available at www.lordabbett.com or by calling 888-522-2388.

Bar Chart (per calendar year) — Class A Shares

Best Quarter 2nd Q ’09 +25.22% Worst Quarter 4th Q ’08 -25.10%

Average Annual Total Returns (for the periods ended December 31, 2016)

The table below shows how the Fund’s average annual total returns compare to the returns of a securities market index with investment characteristics similar to those of the Fund. The Fund’s average annual total returns include applicable sales charges.

The after-tax returns of Class A shares included in the table below are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. In some cases, the return after taxes on distributions and sale of Fund shares may exceed the return before taxes due to a tax benefit resulting from realized losses on a sale of Fund shares at the end of the period that is used to offset other gains. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements such as 401(k) plans or Individual Retirement Accounts (“IRAs”). After-tax returns for other share classes are not shown in the table and will vary from those shown for Class A shares.

Average Annual Returns - Lord Abbett Alpha Strategy Fund	1 Year	5 Years	10 Years	Life of Class	Inception Date for Performance
Class A	2.93%	10.92%	6.53%
Class B	3.60%	11.14%	6.56%
Class C	7.47%	11.41%	6.42%
Class F	9.39%	12.42%		6.26%	Sep. 28, 2007
Class I	9.52%	12.53%	7.48%
Class R2	8.87%	11.86%		5.73%	Sep. 28, 2007
Class R3	8.96%	11.96%		5.83%	Sep. 28, 2007
Class R4	9.22%			0.26%	Jun. 30, 2015
Class R5	9.51%			0.53%	Jun. 30, 2015
Class R6	9.47%			0.52%	Jun. 30, 2015
After Taxes on Distributions | Class A	0.36%	8.43%	4.99%
After Taxes on Distributions and Sale of Fund Shares | Class A	3.82%	8.45%	5.04%
85% Russell 2000® Index/15% S&P Developed Ex-U.S. SmallCap Index (reflects no deduction for fees, expenses, or taxes) 9/28/2007	18.66%	13.82%	6.57%	6.59%	Sep. 28, 2007
85% Russell 2000® Index/15% S&P Developed Ex-U.S. SmallCap Index (reflects no deduction for fees, expenses, or taxes) 6/30/2015	18.66%	13.82%	6.57%	6.09%	Jun. 30, 2015
Lipper Small-Cap Core Category Average (reflects no deduction for sales charges or taxes) 9/28/2007	20.56%	13.46%	6.88%	6.87%	Sep. 28, 2007
Lipper Small-Cap Core Category Average (reflects no deduction for sales charges or taxes) 6/30/2015	20.56%	13.46%	6.88%	6.89%	Jun. 30, 2015

[1] A contingent deferred sales charge ("CDSC") of 1.00% may be assessed on certain Class A shares purchased or acquired without a sales charge if they are redeemed before the first day of the month of the one-year anniversary of the purchase.

[2] A CDSC of 1.00% may be assessed on Class C shares if they are redeemed before the first anniversary of their purchase.

[1] Lord Abbett presently is waiving the Fund's entire management fee on a voluntary basis. This voluntary management fee waiver may be discontinued at any time without notice.

[2] Based on estimated amounts for the current fiscal year.