explorerfundspi024102010.htm - Generated by SEC Publisher for SEC Filing

Vanguard Explorer^™Fund

Summary Prospectus

October 14, 2010

Investor Shares for Participants

Vanguard Explorer Fund Investor Shares (VEXPX)

The Fund’s statutory Prospectus and Statement of Additional Information dated

October 14, 2010, and financial highlights information from the most recent

shareholder report are incorporated into and made part of this Summary

Prospectus by reference.

Before you invest, you may want to review the Fund’s Prospectus, which

contains more information about the Fund and its risks. You can find

the Fund’s Prospectus and other information about the Fund online at

www.vanguard.com/prospectus. You can also get this information at

no cost by calling 800-523-1188 or by sending an e-mail request to

online@vanguard.com.

The Securities and Exchange Commission has not approved or disapproved these securities or passed

upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Investment Objective

The Fund seeks to provide long-term capital appreciation.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy and hold Investor Shares of the Fund.


Shareholder Fees
(Fees paid directly from your investment)
Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None


Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)
Management Expenses	0.50%
12b-1 Distribution Fee	None
Other Expenses	0.04%
Total Annual Fund Operating Expenses	0.54%

Example

The following example is intended to help you compare the cost of investing in the Fund’s Investor Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you invest $10,000 in the Fund’s shares. This example assumes that the Shares provide a return of 5% a year and that operating expenses remain as stated. The results apply whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:


1 Year	3 Years	5 Years	10 Years
$55	$173	$302	$677

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 previous expense example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 95% of the average value of its portfolio.

Primary Investment Strategies

The Fund invests mainly in the stocks of small companies. These companies tend to be unseasoned but are considered by the Fund’s advisors to have superior growth potential. Also, these companies often provide little or no dividend income. The Fund uses multiple investment advisors.

Primary Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range, like the fluctuations of the overall stock market. The Fund’s performance could be hurt by:

• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices.

• Investment style risk, which is the chance that returns from small-capitalization growth stocks will trail returns from the overall stock market. Historically, small-cap stocks have been more volatile in price than the large-cap stocks that dominate the overall market, and they often perform quite differently.

• Manager risk, which is the chance that poor security selection or focus on securities in a particular sector, category, or group of companies will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective.

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.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund‘s Investor Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns compare with those of a relevant market index. Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future. Updated performance information is available on our website at www.vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2010, was 10.87%.

During the periods shown in the bar chart, the highest return for a calendar quarter was 25.18% (quarter ended December 31, 2001), and the lowest return for a quarter was –26.16% (quarter ended December 31, 2008).


Average Annual Total Returns for Periods Ended December 31, 2009
	1 Year	5 Years	10 Years
Vanguard Explorer Fund Investor Shares	36.21%	0.44%	3.35%
Russell 2500 Growth Index
(reflects no deduction for fees or expenses)	41.66%	2.00%	–0.18%

Investment Advisors
Century Capital Management, LLC

Chartwell Investment Partners, L.P.

Granahan Investment Management, Inc.

Kalmar Investment Advisers

Wellington Management Company, LLP

The Vanguard Group, Inc.

Portfolio Managers

Alexander L. Thorndike, Chief Investment Officer and Managing Partner at Century Capital. He has managed a portion of the Fund since 2008.

Edward N. Antoian, CFA, CPA, Managing Partner at Chartwell. He has co-managed a portion of the Fund since 1997.

John Heffern, Managing Partner at Chartwell. He has co-managed a portion of the Fund since 2006.

John J. Granahan, CFA, Founder and President of Granahan. He has managed a portion of the Fund since 1990.

Ford B. Draper, Jr., President, Chief Investment Officer, and Founder of Kalmar. He has managed a portion of the Fund since 2005.

Kenneth L. Abrams, Senior Vice President and Equity Portfolio Manager of Wellington Management. He has managed a portion of the Fund since 1994.

James D. Troyer, CFA, Principal of Vanguard. He has managed a portion of the Fund since 2006.

Tax Information

The Fund’s distributions will be reinvested in additional Fund shares and accumulate on a tax-deferred basis if you are investing through an employer-sponsored retirement or savings plan. You will not owe taxes on these distributions until you begin withdrawals from the plan. You should consult your plan administrator, your plan’s Summary Plan Description, or your tax advisor about the tax consequences of plan withdrawals.

Payments to Financial Intermediaries

The Fund and its investment advisors do not pay financial intermediaries for sales of Fund shares.

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