explorer485a.htm - Generated by SEC Publisher for SEC Filing

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form N-1A

REGISTRATION STATEMENT (NO. 2-27203)
UNDER THE SECURITIES ACT OF 1933 [X]

Pre-Effective Amendment No. [ ]

Post-Effective Amendment No. 88 [X]

and

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940

Amendment No. 89

[X]

VANGUARD EXPLORER FUND

(Exact Name of Registrant as Specified in Declaration of Trust)

P.O. Box 2600, Valley Forge, PA 19482

(Address of Principal Executive Office)

Registrant’s Telephone Number (610) 669-1000

Heidi Stam, Esquire

P.O. Box 876

Valley Forge, PA 19482

Approximate Date of Proposed Public Offering:

It is proposed that this filing will become effective (check appropriate box)

[ ] immediately upon filing pursuant to paragraph (b)

[ ] on (date) pursuant to paragraph (b)

[ ] 60 days after filing pursuant to paragraph (a)(1)

[X] on October 14, 2010 pursuant to paragraph (a)(1)

[ ] 75 days after filing pursuant to paragraph (a)(2)

[ ] on (date) pursuant to paragraph (a)(2) of rule 485

If appropriate, check the following box:

[ ] This post-effective amendment designates a new effective date for a

previously filed post-effective amendment.

Fund Summary

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 or Admiral Shares of the Fund.


Shareholder Fees
(Fees paid directly from your investment)
	Investor Shares	Admiral Shares
Sales Charge (Load) Imposed on Purchases	None	None
Purchase Fee	None	None
Sales Charge (Load) Imposed on Reinvested Dividends	None	None
Redemption Fee	None	None
Account Service Fee (for fund account balances below $10,000)	$20/year	None

Annual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)
	Investor Shares	Admiral Shares
Management Expenses	0.XX%	0.XX%
12b-1 Distribution Fee	None	None
Other Expenses	0.XX%	0.XX%
Total Annual Fund Operating Expenses	0.XX%	0.XX%

Examples

The following examples are intended to help you compare the cost of investing in the Fund’s Investor Shares or Admiral Shares with the cost of investing in other mutual funds. They illustrate the hypothetical expenses that you would incur over various periods if you invest $10,000 in the Fund’s shares. These examples assume that the Shares provide a return of 5% a year and that operating expenses remain the same. 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
Investor Shares	$XX	$XX	$XX	$XX
Admiral Shares	$XX	$XX	$XX	$XX

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 XX% 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 of the share classes presented compare with those of a relevant market index. Keep in mind that the Fund’s past performance (before and after taxes) 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.

Annual Total Returns—Investor Shares¹

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

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
Return Before Taxes	36.21%	0.44%	3.35%
Return After Taxes on Distributions	36.17	–0.58	2.14
Return After Taxes on Distributions and Sale of Fund Shares	23.58	0.28	2.42
Russell 2500 Growth Index
(reflects no deduction for fees, expenses, or taxes)	41.66%	2.00%	–0.18%
			Since
			Inception
			(Nov. 12,
	1 Year	5 Years	2001)
Vanguard Explorer Fund Admiral Shares
Return Before Taxes	36.45%	0.62%	4.57%
Russell 2500 Growth Index
(reflects no deduction for fees, expenses, or taxes)	41.66%	2.00%	4.67%

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are shown only for the Investor Shares and may differ for each share class. After-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares will be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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.

Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website at www.vanguard.com, by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The following table provides the Fund’s minimum initial and subsequent investment requirements.


Account Minimums	Investor Shares	Admiral Shares
To open and maintain an account	$3,000	$100,000
To add to an existing account	$100 (other than by Automatic	$100 (other than by Automatic
	Investment Plan, which	Investment Plan, which
	has no established minimum)	has no established minimum)

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain.

Payments to Financial Intermediaries

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

More on the Fund

This prospectus describes the primary risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: The higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: The lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations

in the securities markets. Look for this

symbol throughout the prospectus. It is

used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^®explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

The Fund offers two separate classes of shares: Investor Shares and Admiral Shares.

Both share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment performances will differ.

Plain Talk About Fund Expenses

All mutual funds have operating expenses. These expenses, which are deducted

from a fund’s gross income, are expressed as a percentage of the net assets of

the fund. Vanguard Explorer Fund’s expense ratios in fiscal year 2010 were as

follows: for Investor Shares, 0.XX%, or $XX per $1,000 of average net assets; for

Admiral Shares, 0.XX%, or $XX per $1,000 of average net assets. The average

expense ratio for small-cap growth funds in 2009 was XX%, or $XX per $1,000 of

average net assets (derived from data provided by Lipper Inc., which reports on

the mutual fund industry). Management expenses, which are one part of

operating expenses, include investment advisory fees as well as other costs of

managing a fund—such as account maintenance, reporting, accounting, legal,

and other administrative expenses.

Plain Talk About Costs of Investing

Costs are an important consideration in choosing a mutual fund. That’s because

you, as a shareholder, pay the costs of operating a fund, plus any transaction

costs incurred when the fund buys or sells securities. These costs can erode a

substantial portion of the gross income or the capital appreciation a fund

achieves. Even seemingly small differences in expenses can, over time, have a

dramatic effect on a fund’s performance.

The following sections explain the primary investment strategies and policies that the Fund uses in pursuit of its objective. The Fund’s board of trustees, which oversees the Fund’s management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental.

Market Exposure

The Fund focuses on companies that are considered small-cap by the Fund’s advisors.

Stocks of publicly traded companies and funds that invest in stocks are often classified according to market value, or market capitalization. These classifications typically include small-cap, mid-cap, and large-cap. It’s important to understand that, for both companies and stock funds, market-capitalization ranges change over time. Also, interpretations of size vary, and there are no “official” definitions of small-, mid-, and large-cap, even among Vanguard fund advisors. The asset-weighted median market capitalization of the Fund as of April 30, 2010, was $XX billion.

Small-cap stocks tend to have greater volatility than large-cap stocks because, among other things, smaller companies often have fewer customers, financial resources, and products than larger firms. Such characteristics can make small-cap companies more sensitive to changing economic conditions. In addition, these companies typically provide little or no dividend income.

The Fund is subject to 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.

To illustrate the volatility of stock prices, the following table shows the best, worst, and average annual total returns for the U.S. stock market over various periods as measured by the Standard & Poor‘s 500 Index, a widely used barometer of market activity. (Total returns consist of dividend income plus change in market price.) Note that the returns shown do not include the costs of buying and selling stocks or other expenses that a real-world investment portfolio would incur.


U.S. Stock Market Returns
(1926–2009)
	1 Year	5 Years	10 Years	20 Years
Best	54.2%	28.6%	19.9%	17.8%
Worst	–43.1	–12.4	–1.4	3.1
Average	11.8	10.1	10.7	11.3

The table covers all of the 1-, 5-, 10-, and 20-year periods from 1926 through 2009. You can see, for example, that although the average return on common stocks for all of the 5-year periods was 10.1%, average returns for individual 5-year periods ranged from –12.4% (from 1928 through 1932) to 28.6% (from 1995 through 1999). These average returns reflect past performance of common stocks; you should not regard them as an indication of future performance of either the stock market as a whole or the Fund in particular.

Keep in mind that the Fund focuses on the stocks of smaller companies. Historically, small-cap stocks have been more volatile than—and at times have performed quite differently from—the large-cap stocks found in the S&P 500 Index. This volatility is due to several factors, including less-certain growth and dividend prospects for smaller companies.

The Fund is subject to 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.

Plain Talk About Growth Funds and Value Funds

Growth investing and value investing are two styles employed by stock-fund

managers. Growth funds generally focus on stocks of companies believed to

have above-average potential for growth in revenue, earnings, cash flow, or other

similar criteria. These stocks typically have low dividend yields and above-average

prices in relation to such measures as earnings and book value. Value funds

typically emphasize stocks whose prices are below average in relation to those

measures; these stocks often have above-average dividend yields. Growth and

value stocks have historically produced similar long-term returns, though each

category has periods when it outperforms the other.

Security Selection

The Fund uses multiple investment advisors. Each advisor independently selects and maintains a portfolio of common stocks for the Fund.

Each advisor employs active investment management methods, which means that securities are bought and sold according to the advisors’ evaluations of companies and their financial prospects, the prices of the securities, and the stock market and the economy in general. Each advisor will sell a security when it is no longer as attractive as an alternative investment.

Each advisor uses a different process to select securities for its portion of the Fund’s assets; however, each is committed to buying stocks of small companies that, in the advisor's opinion, have strong growth potential.

Granahan Investment Management, Inc. (Granahan), which manages approximately XX% of the Fund’s assets, groups securities into three categories as part of its selection process. The first category, “core growth,” emphasizes companies that have a well-known or established product or service and, as a result, have a proven record of growth and a strong market position. The second category, “pioneers,” is made up of companies that offer unique products or services, technologies that may lead to new products, or expansion into new markets. Granahan judges “pioneer” stocks based on their estimated growth potential compared with market value. The third category, “special situation,” includes companies that lack a record of strong growth but that, in Granahan’s view, are both undervalued in the market and likely to grow in the next few years. “Core growth” stocks generally make up 35% to 70% of the advisor’s share of Fund assets, with the other two categories generally at 10% to 35% each.

Wellington Management Company, LLP (Wellington Management), which manages approximately XX% of the Fund’s assets, uses research and analysis of individual companies to select stocks that the advisor feels have exceptional growth potential relative to their valuations in the marketplace. Wellington Management considers each stock individually before purchase, and continually monitors developments at these companies for comparison with the advisor’s expectations for growth. To help limit risk, the portfolio is broadly diversified both by number of stocks and by exposure to a range of industries.

undervalued levels, and own them for the longer term. Kalmar searches for companies that it believes have the following characteristics: strong products, strong balance sheets, attractive financial returns, conservative accounting, and superior management with the ability to deliver positive results.

Chartwell Investment Partners, L.P. (Chartwell), which manages approximately XX% of the Fund’s assets, uses a research-driven process to choose stocks judged to have exceptional growth potential and reasonable prices. After considering each stock individually before purchase, Chartwell constantly monitors the characteristics of its holdings as a group by using computerized techniques.

Century Capital Management, LLC (Century Capital), which manages approximately XX% of the Fund’s assets, employs a fundamental, bottom-up investment approach that attempts to identify reasonably priced companies that will grow faster than the overall market. Independent research is a core tenet. Analysts are expected to make at least 80 company visits per year, including meeting with the second or third tier of management. The ideal investment is a reasonably valued, well-managed company in a non-capital-intensive business. Such a company would also need to have established products or services, a high return on equity, high recurring revenues, and improving margins.

The Vanguard Group, Inc. (Vanguard), manages approximately XX% of the Fund’s assets by constructing a broadly diversified portfolio of small-cap domestic growth stocks based on its assessment of the relative return potential of the underlying securities. The advisor selects securities that it believes offer a good balance between reasonable valuations and attractive earnings growth prospects relative to their small-cap domestic growth peers. Vanguard implements its stock selection process through the use of proprietary software programs that compare thousands of securities at a time.

In addition, Vanguard manages approximately XX% of the Fund’s assets, by investing in stock index futures and/or shares of exchange-traded funds. For more details, see “Other Investment Policies and Risks.”

The Fund is subject to 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.

The Fund is generally managed without regard to tax ramifications.

Other Investment Policies and Risks

Besides investing in common stocks of growth companies, the Fund may make other kinds of investments to achieve its objective.

Although the Fund typically does not make significant investments in foreign securities, it reserves the right to invest up to 25% of its assets this way. Foreign securities may be traded on U.S. or foreign markets. To the extent that it owns foreign securities, the Fund is subject to country risk and currency risk. Country risk is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value of securities issued by companies in foreign countries. In addition, the prices of foreign stocks and the prices of U.S. stocks have, at times, moved in opposite directions. Currency risk is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates.

The Fund may invest up to 15% of its net assets in restricted securities with limited marketability or in other illiquid securities.

The Fund may invest, to a limited extent, in derivatives. Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, bond, or currency), a physical asset (such as gold), or a market index (such as the S&P 500 Index). Investments in derivatives may subject the Fund to risks different from, and possibly greater than, those of the underlying securities, assets, or market indexes. The Fund will not use derivatives for speculation or for the purpose of leveraging (magnifying) investment returns.

The Fund may enter into forward foreign currency exchange contracts, which are types of derivative contracts. A forward foreign currency exchange contract is an agreement to buy or sell a country’s currency at a specific price on a specific date, usually 30, 60, or 90 days in the future. In other words, the contract guarantees an exchange rate on a given date. Managers of funds that invest in foreign securities can use these contracts to guard against unfavorable changes in U.S. dollar/foreign currency exchange rates. These contracts, however, would not prevent the Fund’s securities from falling in value during foreign market downswings.

Vanguard typically invests a small portion of the Fund’s assets in stock index futures and/or shares of exchange-traded funds (ETFs), including ETF Shares issued by Vanguard stock funds. Stock index futures and ETFs provide returns similar to those of common stocks. Vanguard may purchase futures or ETFs when doing so will reduce the Fund’s transaction costs or add value because the instruments are favorably priced. Vanguard receives no additional revenue from investing Fund assets in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations.

Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives, such as exchange-

traded futures and options on securities, commodities, or indexes, have been

trading on regulated exchanges for decades. These types of derivatives are

standardized contracts that can easily be bought and sold, and whose market

values are determined and published daily. Nonstandardized derivatives (such as

swap agreements), on the other hand, tend to be more specialized or complex,

and may be harder to value.

Cash Management

The Fund’s daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the at-cost expenses of the CMT Fund in which it invests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when doing so is believed to be in the Fund’s best interest, so long as the alternative is consistent with the Fund’s investment objective. For instance, the Fund may invest beyond the normal limits in derivatives or ETFs that are consistent with the Fund’s objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund is transitioning assets from one advisor to another or receives large cash flows that it cannot prudently invest immediately.

In addition, the Fund may take temporary defensive positions that are inconsistent with its normal investment policies and strategies—for instance, by allocating substantial assets to cash, commercial paper, or other less volatile instruments—in response to adverse or unusual market, economic, political, or other conditions. In doing so, the Fund may succeed in avoiding losses but may otherwise fail to achieve its investment objective.

Frequent Trading or Market-Timing

Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund’s shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, a fund incurs costs for buying and selling securities, resulting in increased brokerage and

administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor’s ability to efficiently manage the fund.

Policies to Address Frequent Trading. The Vanguard funds (other than money market funds and short-term bond funds) do not knowingly accommodate frequent trading. Vanguard ETF^®Shares are not subject to these frequent-trading policies. The board of trustees of each Vanguard fund has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some cases, to compensate the fund for the costs associated with it. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:

• Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected if Vanguard determines that such purchase may negatively affect a fund’s operation or performance or because of a history of frequent trading by the investor.

• Each Vanguard fund (other than money market funds and short-term bond funds) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor’s purchases or exchanges into a fund account for 60 calendar days after the investor has redeemed or exchanged out of that fund account.

• Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

See the Investing With Vanguard section of this prospectus for further details on Vanguard’s transaction policies.

Each fund (other than money market funds), in determining its net asset value, will, when appropriate, use fair-value pricing, as described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.

Do not invest with Vanguard if you are a market-timer.

Turnover Rate

Although the Fund normally seeks to invest for the long term, it may sell securities regardless of how long they have been held. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. The average turnover rate for small growth funds was approximately 135%, as reported by Morningstar, Inc., on April 30, 2010.

Plain Talk About Turnover Rate

Before investing in a mutual fund, you should review its turnover rate. This gives

an indication of how transaction costs, which are not included in the fund’s

expense ratio, could affect the fund’s future returns. In general, the greater the

volume of buying and selling by the fund, the greater the impact that brokerage

commissions and other transaction costs will have on its return. Also, funds with

high turnover rates may be more likely to generate capital gains that must be

distributed to shareholders as taxable income.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of 37 investment companies with more than 160 funds holding assets of approximately $XX trillion. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, equipment, and advertising.

Vanguard also provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of The Vanguard Group’s marketing costs.

Plain Talk About Vanguard’s Unique Corporate Structure

The Vanguard Group is truly a mutual mutual fund company. It is owned jointly by

the funds it oversees and thus indirectly by the shareholders in those funds.

Most other mutual funds are operated by management companies that may be

owned by one person, by a private group of individuals, or by public investors

who own the management company’s stock. The management fees charged by

these companies include a profit component over and above the companies’ cost

of providing services. By contrast, Vanguard provides services to its member

funds on an at-cost basis, with no profit component, which helps to keep the

funds’ expenses low.

Investment Advisors

The Fund uses a multimanager approach. Each advisor independently manages its assigned portion of the Fund’s assets, subject to the supervision and oversight of Vanguard and the Fund’s board of trustees. The board of trustees designates the

proportion of Fund assets to be managed by each advisor and may change these proportions at any time.

• Century Capital Management, LLC, 100 Federal Street, Boston, MA 02110, is an investment advisory firm that provides investment management services to institutions and individuals. The firm traces its origins to 1928 and the founding of Century Shares Trust. As of April 30, 2010, Century Capital managed approximately $xx billion in assets.

• Chartwell Investment Partners, L.P., 1235 Westlakes Drive, Suite 400, Berwyn, PA

19312, is an investment advisory firm founded in 1997. As of April 30, 2010, Chartwell managed approximately $xx billion in assets.

• Granahan Investment Management, Inc., 275 Wyman Street, Waltham, MA 02451, is an investment advisory firm founded in 1985. As of April 30, 2010, Granahan managed approximately $xx billion in assets.

• Kalmar Investment Advisers, Barley Mill House, 3701 Kennett Pike, Wilmington, DE

19807, is an investment advisory firm founded in 1996. As of April 30, 2010, Kalmar, together with its sister company, Kalmar Investments Inc., founded in 1982, managed approximately $x.x billion in small-cap and small-/mid-cap assets.

• Wellington Management Company, LLP, 75 State Street, Boston, MA 02109, is a Massachusetts limited liability partnership and an investment counseling firm that provides investment services to investment companies, employee benefit plans, endowments, foundations, and other institutions. Wellington Management and its predecessor organizations have provided investment advisory services for over 70 years. As of April 30, 2010, Wellington Management had investment management authority with respect to approximately $xx billion in assets. The firm-wide asset totals do not include agency mortgage-backed security pass-through accounts managed for the Federal Reserve.

• The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Quantitative Equity Group. As of April 30, 2010, Vanguard served as advisor for approximately $XX trillion in assets.

The Fund pays each of its investment advisors (other than Vanguard) a base fee plus or minus a performance adjustment. Each base fee, which is paid quarterly, is a percentage of average daily net assets managed by the advisor during the most recent fiscal quarter. The base fee has breakpoints, which means that the percentage declines as assets go up. The performance adjustment, also paid quarterly, is based on the cumulative total return of each advisor’s portion of the Fund relative to that of the Russell 2500 Growth Index over the preceding 36-month period. When the performance adjustment is positive, the Fund’s expenses increase; when it is negative, expenses decrease.

Vanguard provides services to the Fund on an at-cost basis. Vanguard’s performance is also evaluated against the Russell 2500 Growth Index.

For the fiscal year ended April 30, 2010, the aggregate advisory fees and expenses paid to the Fund’s advisors represented an effective annual rate of XX% of the Fund’s average net assets before a performance-based decrease of XX%.

Under the terms of an SEC exemption, the Fund’s board of trustees may, without prior approval from shareholders, change the terms of an advisory agreement or hire a new investment advisor—either as a replacement for an existing advisor or as an additional advisor. Any significant change in the Fund’s advisory arrangements will be communicated to shareholders in writing. As the Fund’s sponsor and overall manager, The Vanguard Group may provide additional investment advisory services to the Fund, on an at-cost basis, at any time. Vanguard may also recommend to the board of trustees that an advisor be hired, terminated, or replaced, or that the terms of an existing advisory agreement be revised.

For a discussion of why the board of trustees approved the Fund’s investment advisory arrangements, see the most recent semiannual report to shareholders covering the fiscal period ended April 30.

Vanguard’s Quantitative Equity Group is overseen by:

George U. Sauter, Chief Investment Officer and Managing Director of Vanguard. As Chief Investment Officer, he is responsible for the oversight of Vanguard’s Quantitative Equity and Fixed Income Groups. The investments managed by these two groups include active quantitative equity funds, equity index funds, active bond funds, index bond funds, stable value portfolios, and money market funds. Since joining Vanguard in 1987, Mr. Sauter has been a key contributor to the development of Vanguard’s stock indexing and active quantitative equity investment strategies. He received his A.B. in Economics from Dartmouth College and an M.B.A. in Finance from the University of Chicago.

Sandip A. Bhagat, CFA, Principal of Vanguard and head of Vanguard’s Quantitative Equity Group. He has oversight responsibility for all active quantitative equity funds and all equity index funds managed by the Quantitative Equity Group. He has managed investment portfolios since 1987 and has been with Vanguard since 2009. He received his B.S. in Chemical Engineering from the University of Bombay, India, and an M.S. in Chemical Engineering and an M.B.A. from the University of Connecticut.

Joel M. Dickson, Ph.D., Principal of Vanguard and head of Vanguard’s Active Quantitative Equity Management. He has direct oversight responsibility for all active quantitative equity funds managed by the Quantitative Equity Group. He has been with Vanguard since 1996 and has managed investment portfolios since 2003. He received

his A.B. in Economics from Washington University in St. Louis and a Ph.D. in Economics from Stanford University.

The managers primarily responsible for the day-to-day management of the Fund are:

Alexander L. Thorndike, Chief Investment Officer and Managing Partner at Century Capital. He has worked in investment management since 1988; has managed investment portfolios for Century Capital since 1999; and has managed a portion of the Fund since 2008. Education: A.B., Harvard University; M.B.A., J.L. Kellogg Graduate School of Management at Northwestern University.

Edward N. Antoian, CFA, CPA, Managing Partner at Chartwell. He has managed equity funds since 1984 and has co-managed a portion of the Fund since 1997. Education: B.S., State University of New York; M.B.A., University of Pennsylvania.

John Heffern, Managing Partner at Chartwell. He has worked in investment management since 1988; has been with Chartwell since 2005; and has co-managed a portion of the Fund since 2006. Education: B.S. and M.B.A., University of North Carolina at Chapel Hill.

John J. Granahan, CFA, Founder and President of Granahan. He has worked in investment management since 1960; has been with Granahan since 1985; and has managed a portion of the Fund since 1990. Education: B.A., St. Joseph’s University; Graduate Fellow of Catholic University of America.

Ford B. Draper, Jr., President, Chief Investment Officer, and Founder of Kalmar. He has worked in investment management since 1967; founded Kalmar Investments Inc., the sister company of Kalmar, in 1982; and has managed a portion of the Fund since 2005. Education: B.A., Yale University; M.B.A., Columbia University.

Kenneth L. Abrams, Senior Vice President, and Equity Portfolio Manager at Wellington Management. He has worked in investment management with Wellington Management since 1986 and has managed a portion of the Fund since 1994. Education: B.A. and M.B.A., Stanford University.

James D. Troyer, CFA, Principal of Vanguard. He has worked in investment management since 1979; has managed investment portfolios for Vanguard since 1989; and has managed a portion of the Fund since 2006. Education: A.B., Occidental College.

The Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest and dividends, less expenses) as well as any net capital gains realized from the sale of its holdings. Distributions generally occur annually in December. You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund’s income from interest

and dividends as well as capital gains from the fund’s sale of investments. Income

consists of both the dividends that the fund earns from any stock holdings and the

interest it receives from any money market and bond investments. Capital gains are

realized whenever the fund sells securities for higher prices than it paid for them.

These capital gains are either short-term or long-term, depending on whether the

fund held the securities for one year or less or for more than one year.

Basic Tax Points

Vanguard will send you a statement each year showing the tax status of all your distributions. In addition, investors in taxable accounts should be aware of the following basic federal income tax points:

• Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares.

• Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

• Any dividend and short-term capital gains distributions that you receive are taxable to you as ordinary income. If you are an individual and meet certain holding-period requirements with respect to your Fund shares, you may be eligible for reduced tax rates on “qualified dividend income,”if any, distributed by the Fund.

• Any distributions of net long-term capital gains are taxable to you as long-term capital gains, no matter how long you’ve owned shares in the Fund.

• Capital gains distributions may vary considerably from year to year as a result of the Fund‘s normal investment activities and cash flows.

• A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

• Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

Dividend and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes.

This prospectus provides general tax information only. If you are investing through a tax-deferred retirement account, such as an IRA, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

Plain Talk About ‘Buying a Dividend’

Unless you are investing through a tax-deferred retirement account (such as an

IRA), you should consider avoiding a purchase of fund shares shortly before the

fund makes a distribution, because doing so can cost you money in taxes. This is

known as “buying a dividend.” For example: On December 15, you invest $5,000,

buying 250 shares for $20 each. If the fund pays a distribution of $1 per share on

December 16, its share price will drop to $19 (not counting market change). You

still have only $5,000 (250 shares x $19 = $4,750 in share value, plus 250 shares

x $1 = $250 in distributions), but you owe tax on the $250 distribution you

received—even if you reinvest it in more shares. To avoid “buying a dividend,”

check a fund’s distribution schedule before you invest.

General Information

Backup withholding. By law, Vanguard must withhold 28% of any taxable distributions or redemptions from your account if you do not:

• Provide us with your correct taxpayer identification number;

• Certify that the taxpayer identification number is correct; and

• Confirm that you are not subject to backup withholding.

Similarly, Vanguard must withhold taxes from your account if the IRS instructs us to do so.

Foreign investors. Vanguard funds generally are not sold outside the United States, except to certain qualified investors. If you reside outside the United States, please consult our website at www.vanguard.com and review “Non-U.S. investors.” Foreign investors should be aware that U.S. withholding and estate taxes may apply to any investments in Vanguard funds.

Invalid addresses. If a dividend or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest all future distributions until you provide us with a valid mailing address.

Share Price

Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange, generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to each share class by the number of Fund shares outstanding for that class. On holidays or other days when the Exchange is closed, the NAV is not calculated, and the Fund does not transact purchase or redemption requests. However, on those days the value of the Fund’s assets may be affected to the extent that the Fund holds foreign securities that trade on foreign markets that are open.

Stocks held by a Vanguard fund are valued at their market value when reliable market quotations are readily available. Certain short-term debt instruments used to manage a fund’s cash are valued on the basis of amortized cost. The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party. The values of any mutual fund shares held by a fund are based on the NAVs of the shares. The values of any ETF or closed-end fund shares held by a fund are based on the market value of the shares.

When a fund determines that market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security). A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund’s pricing time but after the close of the primary markets or exchanges on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges that close many hours before the fund’s pricing time. Intervening events might be company-specific (e.g., earnings report, merger announcement); country-specific (e.g., natural disaster, economic or political news, act of terrorism, interest rate change); or global. Intervening events include price movements in U.S. markets that are deemed to affect the value of foreign securities. Fair-value pricing may be used for domestic securities—for example, if (1) trading in a security is halted and does not resume before the fund’s pricing time or if a security does not trade in the course of a day, and (2) the fund holds enough of the security that its price could affect the NAV.

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard fund share prices are published daily on our website at www.vanguard.com/prices.

Financial Highlights

The following financial highlights tables are intended to help you understand the Fund’s financial performance for the periods shown, and certain information reflects financial results for a single Fund share. The total returns in each table represent the rate that an investor would have earned or lost each period on an investment in the Fund (assuming reinvestment of all distributions). The information for the six-month period ended April 30, 2010, has not been audited by an independent registered public accounting firm. The information for all periods in each table through October 31, 2009, have been derived from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report—along with the Fund’s financial statements—is included in the Fund‘s most recent annual report to shareholders. You may obtain a free copy of the latest annual or semiannual report online at www.vanguard.com or by contacting Vanguard by telephone or mail.

Plain Talk About How to Read the Financial Highlights Tables

This explanation uses the Fund’s Investor Shares as an example. The Investor

Shares began fiscal period ended April 30, 2010, with a net asset value (price) of

$xx.xx per share. During the period, each Investor Share earned $x.xx from

investment income (interest and dividends) and $xx.xx from investments that had

appreciated in value or that were sold for higher prices than the Fund paid

for them.

Shareholders received $x.xx per share in the form of dividend and capital gains

distributions. A portion of each year’s distributions may come from the prior

year’s income or capital gains.

The share price at the end of the period was $xx.xx, reflecting earnings of $xx.xx

per share and distributions of $x.xx per share. This was an increase of $xx.xx per

share (from $xx.xx at the beginning of the period to $xx.xx at the end of the

period). For a shareholder who reinvested the distributions in the purchase of

more shares, the total return was xx.xx% for the period.

As of April 30, 2010, the Investor Shares had approximately $xx.x billion in net

assets. For the period, the expense ratio was 0.xx% ($x.xx per $1,000 of net

assets), and the net investment income amounted to x.xx% of average net

assets. The Fund sold and replaced securities valued at xx% of its net assets.


Explorer Fund Investor Shares
Six
Months
Ended
	April 30,			Year Ended October 31,
	2010	2009	2008	2007	2006	2005
Net Asset Value, Beginning of Period	$XX	$45.54	$83.93	$80.26	$76.67	$67.01
Investment Operations
Net Investment Income (Loss)	.XX	.178	.295	.362	.302	.111
Net Realized and Unrealized Gain (Loss)
on Investments	(XX)	6.334	(31.589)	11.052	9.724	9.622
Total from Investment Operations	XX	6.512	(31.294)	11.414	10.026	9.733
Distributions
Dividends from Net Investment Income	XX	(.282)	(.310)	(.320)	(.230)	—
Distributions from Realized Capital Gains	XX	—	(6.786)	(7.424)	(6.206)	(.073)
Total Distributions	XX	(.282)	(7.096)	(7.744)	(6.436)	(.073)
Net Asset Value, End of Period	$XX	$51.77	$45.54	$83.93	$80.26	$76.67
Total Return¹	XX%	14.46% –40.17%		15.31%	13.59%	14.53%
Ratios/Supplemental Data
Net Assets, End of Period (Millions)	$XX	$5,677	$5,026	$8,937	$8,517	$7,836
Ratio of Total Expenses to Average Net
Assets²	XX%	0.54%	0.44%	0.41%	0.46%	0.51%
Ratio of Net Investment Income to Average
Net Assets	XX%	0.38%	0.40%	0.44%	0.36%	0.16%
Turnover Rate	XX%	95%	112%	90%	96%	80%

1 Total returns do not include the account service fee that may be applicable to certain accounts with balances below $10,000.

2 Includes performance-based investment advisory fee increases (decreases) of (0.XX%).

Investing With Vanguard

This section of the prospectus explains the basics of doing business with Vanguard. Be sure to carefully read each topic that pertains to your relationship with Vanguard. Vanguard reserves the right to change the following policies, without notice to shareholders. Please call or check online for current information.

Each fund you hold in an account is a separate “fund account.” For example, if you hold three funds in a nonretirement account titled in your own name, two funds in a nonretirement account titled jointly with your spouse, and one fund in an individual retirement account, you have six fund accounts—and this is true even if you hold the same fund in multiple accounts.

Purchasing Shares

Vanguard reserves the right, without notice, to increase or decrease the minimum amount required to open, convert shares to, or maintain a fund account, or to add to an existing fund account.

Investment minimums may differ for certain categories of investors.

Account Minimums for Investor Shares To open and maintain an account. $3,000.

Add to an existing account. $100 by check, exchange, wire, or electronic bank transfer (other than Automatic Investment Plan, which has no established minimum).

Account Minimums for Admiral Shares

To open and maintain an account. $100,000 for new investors. If you request Admiral Shares when you open a new account, but the investment amount does not meet the account minimum for Admiral Shares, your investment will be placed in Investor Shares of the Fund. Shareholders who are registered on Vanguard.com, have held shares of the Fund for ten years, and have $50,000 or more in the same Fund account are eligible to convert their Investor Shares to Admiral Shares. See Converting Shares. Institutional clients should contact Vanguard for information on special rules that may apply to them.

Add to an existing account. $100 by check, exchange, wire, or electronic bank transfer (other than Automatic Investment Plan, which has no established minimum).

How to Initiate a Purchase Request

Be sure to check Exchanging Shares, Frequent-Trading Limits, and Other Rules You Should Know before placing your purchase request.

Online. You may open certain types of accounts, request a purchase of shares, and request an exchange (the purchase of shares of one Vanguard fund using the proceeds of a simultaneous redemption of shares of another Vanguard fund) through our website at www.vanguard.com if you are a registered user.

By telephone. You may call Vanguard to begin the account registration process or request that the account-opening forms be sent to you. You may also call Vanguard to request a purchase of shares. See Contacting Vanguard.

By mail. You may send Vanguard your account registration form and check to open a new fund account. To add to an existing fund account, you may send your check with an Invest-by-Mail form (from your account statement), with a deposit slip (available online), or with a written request. You may also send a written request to Vanguard to make an exchange. For a list of Vanguard addresses, see Contacting Vanguard.

How to Pay for a Purchase

By electronic bank transfer. You may purchase shares of a Vanguard fund through an electronic transfer of money from a bank account. To establish the electronic bank transfer option on an account, you must designate the bank account online, complete a special form, or fill out the appropriate section of your account registration form. After the option is set up on your account, you can purchase shares by electronic bank transfer on a regular schedule (Automatic Investment Plan) or from time to time. Your purchase request can be initiated online (if you are a registered user of Vanguard.com), by telephone, or by mail.

By wire. Wiring instructions vary for different types of purchases. Please call Vanguard for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

By check. You may send a check to make initial or additional purchases to your fund account. Also see How to Initiate a Purchase Request: By mail. Make your check payable to Vanguard and include the appropriate fund number (e.g., Vanguard—xx). For a list of Fund numbers (for share classes in this prospectus), see Additional Information.

By exchange. You may purchase shares of a Vanguard fund using the proceeds from the simultaneous redemption of shares of another Vanguard fund. You may initiate an exchange online (if you are a registered user of Vanguard.com), by telephone, or by mail. See Exchanging Shares.

Trade Date

The trade date for any purchase request received in good order will depend on the day and time Vanguard receives your request, the manner in which you are paying, and the type of fund you are purchasing. Your purchase will be executed using the NAV as

calculated on the trade date. NAVs are calculated only on days that the New York Stock Exchange (NYSE) is open for trading (a business day).

For purchases by check into all funds other than money market funds, and for purchases by exchange or wire into all funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

For purchases by check into money market funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the next business day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the second business day following the day Vanguard receives the purchase request. Because money market instruments must be purchased with federal funds and it takes a money market mutual fund one business day to convert check proceeds into federal funds, the trade date will be one business day later than for other funds.

For purchases by electronic bank transfer using an Automatic Investment Plan: Your trade date generally will be one business day before the date you designated for withdrawal from your bank account.

For purchases by electronic bank transfer not using an Automatic Investment Plan: If the purchase request is received by Vanguard on a business day before 10 p.m., Eastern time, the trade date generally will be the next business day. If the purchase request is received on a business day after 10 p.m., Eastern time, or on a nonbusiness day, the trade date will be the second business day following the day Vanguard receives the request.

If your purchase request is not accurate and complete, it may be rejected. See Other Rules You Should Know—Good Order.

For further information about purchase transactions, consult our website at www.vanguard.com or see Contacting Vanguard.

Other Purchase Rules You Should Know

Admiral Shares. Please note that Admiral Shares are not available for:

• SIMPLE IRAs and Section 403(b)(7) custodial accounts;

• Other retirement plan accounts receiving special administrative services from Vanguard; or

• Accounts maintained by financial intermediaries, except in limited circumstances.

Check purchases. All purchase checks must be written in U.S. dollars and must be drawn on a U.S. bank. Vanguard does not accept cash, traveler’s checks, or money orders. In addition, Vanguard may refuse “starter checks” and checks that are not made payable to Vanguard.

New accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, Vanguard reserves the right, without notice, to close your account or take such other steps as we deem reasonable.

Refused or rejected purchase requests. Vanguard reserves the right to stop selling fund shares or to reject any purchase request at any time and without notice, including, but not limited to, purchases requested by exchange from another Vanguard fund. This also includes the right to reject any purchase request because of a history of frequent trading by the investor or because the purchase may negatively affect a fund’s operation or performance.

Large purchases. Please call Vanguard before attempting to invest a large dollar amount.

No cancellations. Vanguard will not accept your request to cancel any purchase request once processing has begun. Please be careful when placing a purchase request.

Converting Shares

When a conversion occurs, you receive shares of one class in place of shares of another class of the same fund. At the time of conversion, the dollar value of the “new” shares you receive equals the dollar value of the “old” shares that were converted. In other words, the conversion has no effect on the value of your investment in the fund at the time of the conversion. However, the number of shares you own after the conversion may be greater than or less than the number of shares you owned before the conversion, depending on the net asset values of the two share classes.

A conversion between share classes of the same fund is a nontaxable event.

Trade Date

The trade date for any conversion request received in good order will depend on the day and time Vanguard receives your request. Your conversion will be executed using the NAVs of the different share classes on the trade date. NAVs are calculated only on days that the NYSE is open for trading (a business day).

For a conversion request received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the

same day. For a conversion request received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day. See Other Rules You Should Know.

Conversions From Investor Shares to Admiral Shares

Self-directed conversions. If your account balance in the Fund is at least $100,000, you may ask Vanguard to convert your Investor Shares to Admiral Shares. You can request a conversion online (if you are a registered user of Vanguard.com), by telephone, or by mail. See Contacting Vanguard.

Automatic conversions. Vanguard conducts periodic reviews of account balances and may, if your account balance in the Fund exceeds $100,000, automatically convert your Investor Shares to Admiral Shares. You will be notified before an automatic conversion occurs and will have an opportunity to instruct Vanguard not to effect the conversion.

Tenure conversions. You are eligible for a tenure conversion from Investor Shares to Admiral Shares if you have had an account in the Fund for ten years, that Fund account balance is at least $50,000, and you are registered with Vanguard.com. You can request a tenure conversion online, by telephone, or by mail.

Mandatory Conversions to Investor Shares

If an account no longer meets the balance requirements for Admiral Shares, Vanguard may automatically convert the shares in the account to Investor Shares. A decline in the account balance because of market movement may result in such a conversion. Vanguard will notify the investor in writing before any mandatory conversion occurs.

Redeeming Shares

How to Initiate a Redemption Request

Be sure to check Exchanging Shares, Frequent-Trading Limits, and Other Rules You Should Know before placing your redemption request.

Online. You may request a redemption of shares and request an exchange (using the proceeds from the redemption of shares of one Vanguard fund to simultaneously purchase shares of a different Vanguard fund) through our website at www.vanguard.com if you are a registered user.

By telephone. You may call Vanguard to request a redemption of shares. See

Contacting Vanguard.

By mail. You may send a written request to Vanguard to redeem from a fund account or to make an exchange. See Contacting Vanguard.

How to Receive Redemption Proceeds

By electronic bank transfer. You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer option on an account, you must designate a bank account online, complete a special form, or fill out the appropriate section of your account registration form. After the option is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or from time to time. Your redemption request can be initiated online, by telephone, or by mail.

By wire. When redeeming from a money market fund or a bond fund, you may instruct Vanguard to wire your redemption proceeds ($1,000 minimum) to a previously designated bank account. Wire redemptions generally are not available for Vanguard’s balanced or stock funds. The wire redemption option is not automatic; you must designate a bank account online, complete a special form, or fill out the appropriate section of your account registration form.

By exchange. You may have the proceeds of a Vanguard fund redemption invested directly in shares of another Vanguard fund. You may initiate an exchange online (if you are a registered user of Vanguard.com), by telephone, or by mail.

By check. If you have not chosen another redemption method, Vanguard will mail you a redemption check, generally payable to all registered account owners, normally within two business days of your trade date.

Trade Date

The trade date for any redemption request received in good order will depend on the day and time Vanguard receives your request and the manner in which you are redeeming. Your redemption will be executed using the NAV as calculated on the trade date. NAVs are calculated only on days that the NYSE is open for trading (a business day).

For redemptions by check, exchange, or wire: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

• Note on timing of wire redemptions from money market funds: For telephone requests received by Vanguard on a business day before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Prime Money Market Fund), the redemption proceeds generally will leave Vanguard by the close of business the same day. For telephone requests received by Vanguard on a business day after those cut-off times, or on a nonbusiness day, and for all requests other than by telephone, the

redemption proceeds generally will leave Vanguard by the close of business on the next business day.

• Note on timing of wire redemptions from bond funds: For requests received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the redemption proceeds generally will leave Vanguard by the close of business on the next business day. For requests received by Vanguard on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the redemption proceeds generally will leave Vanguard by the close of business on the second business day after Vanguard receives the request.

For redemptions by electronic bank transfer using an Automatic Withdrawal Plan: Your trade date generally will be the date you designated for withdrawal of funds (redemption of shares) from your Vanguard account. Proceeds of redeemed shares generally will be credited to your designated bank account two business days after your trade date. If the date you designated for withdrawal of funds from your Vanguard account falls on a weekend, holiday, or other nonbusiness day, your trade date will be the previous business day.

For redemptions by electronic bank transfer not using an Automatic Withdrawal Plan: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

If your redemption request is not accurate and complete, it may be rejected. If we are unable to send your redemption proceeds by wire or electronic bank transfer because the receiving institution rejects the transfer, Vanguard will make additional efforts to complete your transaction. If Vanguard is still unable to complete the transaction, we may use your proceeds to purchase new shares of the Fund from which you sold shares for the purpose of the wire or electronic bank transfer transaction. See Other Rules You Should Know—Good Order.

For further information about redemption transactions, consult our website at www.vanguard.com or see Contacting Vanguard.

Other Redemption Rules You Should Know

Documentation for certain accounts. Special documentation may be required to redeem from certain types of accounts, such as trust, corporate, nonprofit, or retirement accounts. Please call us before attempting to redeem from these types of accounts.

Potentially disruptive redemptions. Vanguard reserves the right to pay all or part of a redemption in kind—that is, in the form of securities—if we reasonably believe that a

cash redemption would negatively affect the fund’s operation or performance or that the shareholder may be engaged in market-timing or frequent trading. Under these circumstances, Vanguard also reserves the right to delay payment of the redemption proceeds for up to seven calendar days. By calling us before you attempt to redeem a large dollar amount, you may avoid in-kind or delayed payment of your redemption. Please see Frequent-Trading Limits for information about Vanguard’s policies to limit frequent trading.

Recently purchased shares. Although you can redeem shares at any time, proceeds may not be made available to you until the fund collects payment for your purchase. This may take up to ten calendar days for shares purchased by check or by electronic bank transfer. If you have written a check on a fund with checkwriting privileges, that check may be rejected if your fund account does not have a sufficient available balance.

Share certificates. If you hold shares in certificates, those shares cannot be redeemed, exchanged, or converted until you return the certificates (unsigned) to Vanguard by registered mail. For the correct address, see Contacting Vanguard.

Address change. If you change your address online or by telephone, there may be a 15-day restriction on your ability to request redemptions online and by telephone. You can request a redemption in writing at any time. Confirmations of address changes are sent to both the old and new addresses.

Payment to a different person or address. At your request, we can make your redemption check payable to a different person or send it to a different address. However, this generally requires the written consent of all registered account owners and may require a signature guarantee. You may obtain a signature guarantee from some commercial or savings banks, credit unions, trust companies, or member firms of a U.S. stock exchange. A notary public cannot provide a signature guarantee.

No cancellations. Vanguard will not accept your request to cancel any redemption request once processing has begun. Please be careful when placing a redemption request.

Emergency circumstances. Vanguard funds can postpone payment of redemption proceeds for up to seven calendar days. In addition, Vanguard funds can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days at times when the NYSE is closed or during emergency circumstances, as determined by the SEC.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of one Vanguard fund to simultaneously purchase shares of a different Vanguard fund. You can make exchange requests online (if you are a registered user of Vanguard.com), by telephone, or by mail. See Purchasing Shares and Redeeming Shares.

If the NYSE is open for regular trading (generally until 4 p.m., Eastern time, on a business day) at the time an exchange request is received in good order, the trade date generally will be the same day. See Other Rules You Should Know—Good Order for additional information on all transaction requests.

Vanguard will not accept your request to cancel any exchange request once processing has begun. Please be careful when placing an exchange request.

Please note that Vanguard reserves the right, without notice, to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason.

Frequent-Trading Limits

Because excessive transactions can disrupt management of a fund and increase the fund’s costs for all shareholders, the board of trustees of each Vanguard fund places certain limits on frequent trading in the funds. Each Vanguard fund (other than money market funds and short-term bond funds) limits an investor’s purchases or exchanges into a fund account for 60 calendar days after the investor has redeemed or exchanged out of that fund account. ETF Shares are not subject to these frequent-trading limits. The broker through which you hold your ETF Shares, however, may place certain limits on your ability to purchase and/or sell ETF Shares over any given period.

For Vanguard Retirement Investment Program pooled plans, the policy applies to exchanges made online or by phone.

The frequent-trading policy does not apply to the following:

• Purchases of shares with reinvested dividend or capital gains distributions.

• Transactions through Vanguard’s Automatic Investment Plan, Automatic Exchange Service, Direct Deposit Service, Automatic Withdrawal Plan, Required Minimum Distribution Service, and Vanguard Small Business Online^®.

• Redemptions of shares to pay fund or account fees.

• Transaction requests submitted by mail to Vanguard from shareholders who hold their accounts directly with Vanguard. (Transaction requests submitted by fax, if otherwise permitted, are not mail transactions and are subject to the policy.)

• Transfers and reregistrations of shares within the same fund.

• Purchases of shares by asset transfer or direct rollover.

• Conversions of shares from one share class to another in the same fund.

• Checkwriting redemptions.

• Section 529 college savings plans.

• Certain approved institutional portfolios and asset allocation programs, as well as trades made by Vanguard funds that invest in other Vanguard funds. (Please note that shareholders of Vanguard’s funds of funds are subject to the policy.)

For participants in employer-sponsored defined contribution plans,* the frequent-trading policy does not apply to:

• Purchases of shares with participant payroll or employer contributions or loan repayments.

• Purchases of shares with reinvested dividend or capital gains distributions.

• Distributions, loans, and in-service withdrawals from a plan.

• Redemptions of shares as part of a plan termination or at the direction of the plan.

• Automated transactions executed during the first six months of a participant’s enrollment in the Vanguard Managed Account Program.

• Redemptions of shares to pay fund or account fees.

• Share or asset transfers or rollovers.

• Reregistrations of shares.

• Conversions of shares from one share class to another in the same fund.

• Exchange requests submitted by mail to Vanguard. (Exchange requests submitted by fax, if otherwise permitted, are not mail requests and are subject to the policy.)

* The following Vanguard fund accounts are subject to the frequent-trading policy: SEP-IRAs, SIMPLE IRAs, certain Section 403(b)(7) accounts, and Vanguard Retirement Plans for which Vanguard Fiduciary Trust Company serves as trustee.

Accounts Held by Institutions (Other Than Defined Contribution Plans)

Vanguard will systematically monitor for frequent trading in institutional clients’ accounts. If we detect suspicious trading activity, we will investigate and take appropriate action, which may include applying to a client’s accounts the 60-day policy previously described, prohibiting a client’s purchases of fund shares, and/or revoking the client’s exchange privilege.

Accounts Held by Intermediaries

When intermediaries establish accounts in Vanguard funds for the benefit of their clients, we cannot always monitor the trading activity of the individual clients. However, we review trading activity at the intermediary (omnibus) level, and if we detect suspicious activity, we will investigate and take appropriate action. If necessary, Vanguard may prohibit additional purchases of fund shares by an intermediary, including for the benefit of certain of the intermediary’s clients. Intermediaries also may monitor their clients’ trading activities with respect to Vanguard funds.

For those Vanguard funds that charge purchase or redemption fees, intermediaries will be asked to assess purchase and redemption fees on client accounts and remit these fees to the funds. The application of purchase and redemption fees and frequent-trading policies may vary among intermediaries. There are no assurances that Vanguard will successfully identify all intermediaries or that intermediaries will properly assess purchase and redemption fees or administer frequent-trading policies. If you invest with Vanguard through an intermediary, please read that firm’s materials carefully to learn of any other rules or fees that may apply.

Other Rules You Should Know

Prospectus and Shareholder Report Mailings

Vanguard attempts to eliminate the unnecessary expense of duplicate mailings by sending just one prospectus and/or report when two or more shareholders have the same last name and address. You may request individual prospectuses and reports by contacting our Client Services Department in writing, by telephone, or by e-mail.

Vanguard.com

Registration. If you are a registered user of Vanguard.com, you can use your personal computer to review your account holdings; to buy, sell, or exchange shares of most Vanguard funds; and to perform most other transactions. You must register for this service online.

Electronic delivery. Vanguard can deliver your account statements, transaction confirmations, and fund financial reports electronically. If you are a registered user of Vanguard.com, you can consent to the electronic delivery of these documents by logging on and changing your mailing preference under “Account Profile.” You can revoke your electronic consent at any time online, and we will begin to send paper copies of these documents within 30 days of receiving your revocation.

Telephone Transactions

Automatic. When we set up your account, we’ll automatically enable you to do business with us by telephone, unless you instruct us otherwise in writing.

Tele-Account^®. To conduct account transactions through Vanguard’s automated telephone service, you must first obtain a Personal Identification Number (PIN). Call Tele-Account at 800-662-6273 to obtain a PIN.

Proof of a caller’s authority. We reserve the right to refuse a telephone request if the caller is unable to provide the requested information or if we reasonably believe that the caller is not an individual authorized to act on the account. Before we allow a caller to act on an account, we may request the following information:

• Authorization to act on the account (as the account owner or by legal documentation or other means).

• Account registration and address.

• Fund name and account number, if applicable.

• Other information relating to the caller, the account owner, or the account.

Good Order

We reserve the right to reject any transaction instructions that are not in “good order.” Good order generally means that your instructions include:

• The fund name and account number.

• The amount of the transaction (stated in dollars, shares, or percentage).

Written instructions also must include:

• Signatures of all registered owners.

• Signature guarantees, if required for the type of transaction. (Call Vanguard for specific signature-guarantee requirements.)

• Any supporting documentation that may be required.

The requirements vary among types of accounts and transactions.

Vanguard reserves the right, without notice, to revise the requirements for good order.

Future Trade-Date Requests

Vanguard does not accept requests to hold a purchase, conversion, redemption, or exchange transaction for a future date. All such requests will receive trade dates as previously described in Purchasing Shares, Converting Shares, and Redeeming Shares. Vanguard reserves the right to return future-dated purchase checks.

Accounts With More Than One Owner

If an account has more than one owner or authorized person, Vanguard will accept telephone or online instructions from any one owner or authorized person.

Responsibility for Fraud

Vanguard will not be responsible for any account losses because of fraud if we reasonably believe that the person transacting business on an account is authorized to do so. Please take precautions to protect yourself from fraud. Keep your account information private, and immediately review any account statements that we provide to you. It is important that you contact Vanguard immediately about any transactions or changes to your account that you believe to be unauthorized.

Uncashed Checks

Please cash your distribution or redemption checks promptly. Vanguard will not pay interest on uncashed checks.

Unusual Circumstances

If you experience difficulty contacting Vanguard online, by telephone, or by Tele-Account, you can send us your transaction request by regular or express mail. See

Contacting Vanguard for addresses.

Investing With Vanguard Through Other Firms

You may purchase or sell shares of most Vanguard funds through a financial intermediary, such as a bank, broker, or investment advisor. Please consult your financial intermediary to determine which, if any, shares are available through that firm and to learn about other rules that may apply.

Please see Frequent-Trading Limits—Accounts Held by Intermediaries for information about the assessment of redemption fees and monitoring of frequent trading for accounts held by intermediaries.

Account Service Fee

For most shareholders, Vanguard charges a $20 account service fee on all fund accounts that have a balance below $10,000 for any reason, including market fluctuation. The account service fee applies to both retirement and nonretirement fund accounts and will be assessed on fund accounts in all Vanguard funds, regardless of a fund’s minimum investment amount. The fee, which will be collected by redeeming fund shares in the amount of $20, will be deducted from a fund account only once per calendar year.

If you register on Vanguard.com and elect to receive electronic delivery of statements, reports, and other materials for all of your fund accounts, the account service fee for balances below $10,000 will not be charged, so long as that election remains in effect.

The account service fee also does not apply to the following:

• Money market sweep accounts owned in connection with a Vanguard Brokerage Services^®account.

• Accounts held through intermediaries.

• Accounts held by Voyager, Voyager Select, and Flagship members. Membership is based on total household assets held at Vanguard, with a minimum of $50,000 to qualify for Vanguard Voyager Services^®, $500,000 for Vanguard Voyager Select Services^®, and $1 million for Vanguard Flagship Services^®. Vanguard determines membership by aggregating assets of all eligible accounts held by the investor and

immediate family members who reside at the same address. Aggregate assets include investments in Vanguard mutual funds, Vanguard ETFs^®, annuities through Vanguard, the Vanguard 529 Plan, certain small-business accounts, and employer-sponsored retirement plans for which Vanguard provides recordkeeping services.

• Participant accounts in employer-sponsored defined contribution plans.* Please consult your enrollment materials for the rules that apply to your account.

• Section 529 college savings plans.

* The following Vanguard fund accounts have alternative fee structures: SIMPLE IRAs, certain Section 403(b)(7) accounts, Vanguard Retirement Investment Program pooled plans, and Vanguard Retirement Plans for which Vanguard Fiduciary Trust Company serves as trustee.

Low-Balance Accounts

The Fund reserves the right to liquidate a fund account whose balance falls below the minimum initial investment for any reason, including market fluctuation. This policy applies to nonretirement fund accounts and accounts that are held through intermediaries.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this prospectus, Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time; (2) accept initial purchases by telephone; (3) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred; (4) temporarily freeze any account and/or suspend account services upon initial notification to Vanguard of the death of the shareholder until Vanguard receives required documentation in good order; (5) alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and (6) redeem an account or suspend account privileges, without the owner’s permission to do so, in cases of threatening conduct or activity Vanguard believes to be suspicious, fraudulent, or illegal. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, we reasonably believe they are deemed to be in the best interest of a fund.

Share Classes

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including the types of clients who are eligible to purchase each share class.

Fund and Account Updates

Confirmation Statements

We will send (or provide online, whichever you prefer) a confirmation of your trade date and the amount of your transaction when you buy, sell, exchange, or convert shares. However, we will not send confirmations reflecting only checkwriting redemptions or the reinvestment of dividend or capital gains distributions. For any month in which you had a checkwriting redemption, a Checkwriting Activity Statement will be sent to you itemizing the checkwriting redemptions for that month. Promptly review each confirmation statement that we provide to you by mail or online. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on a confirmation statement, or Vanguard will consider the transaction properly processed.

Portfolio Summaries

We will send (or provide online, whichever you prefer) quarterly portfolio summaries to help you keep track of your accounts throughout the year. Each summary shows the market value of your account at the close of the statement period, as well as all distributions, purchases, redemptions, exchanges, transfers, and conversions for the current calendar year. Promptly review each summary that we provide to you by mail or online. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on the summary, or Vanguard will consider the transaction properly processed.

Tax Statements

For most accounts, we will send annual tax statements to assist you in preparing your income tax returns. These statements, which are generally mailed in January, will report the previous year’s dividends, capital gains distributions, proceeds from the sale of shares from taxable accounts, and distributions from IRAs and other retirement plans. Registered users of Vanguard.com can view these statements online.

Average-Cost Review Statements

For most taxable accounts, an average-cost review statement will accompany the annual Form 1099-B. This statement shows the average cost of shares that you redeemed during the previous calendar year, using the average-cost single-category method, one of the methods established by the IRS and the only method used by

Vanguard. You may want to consult a tax professional to determine if a different method is best for you.

Annual and Semiannual Reports

We will send (or provide online, whichever you prefer) comprehensive reports about Vanguard Explorer Fund twice a year, in June and December. These reports include overviews of the financial markets and provide the following specific Fund information:

Performance assessments and comparisons with industry benchmarks.
Reports from the advisors.
Financial statements with listings of Fund holdings.

Portfolio Holdings

We generally post on our website at www.vanguard.com, in the Portfolio section of the Fund’s Portfolio & Management page, a detailed list of the securities held by the Fund, as of the end of the most recent calendar quarter. This list is generally updated within 30 days after the end of each calendar quarter. Vanguard may exclude any portion of these portfolio holdings from publication when deemed in the best interest of the Fund. We also generally post the ten largest stock portfolio holdings of the Fund and the percentage of the Fund’s total assets that each of these holdings represents, as of the end of the most recent calendar quarter. This list is generally updated within 15 calendar days after the end of each calendar quarter. Please consult the Fund’s Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund’s portfolio holdings.


Contacting Vanguard Web Vanguard.com 24 hours a day, 7 days a week	For the most complete source of Vanguard news For fund, account, and service information For most account transactions For literature requests

Phone Vanguard Tele-Account^®800-662-6273 (ON-BOARD)	For automated fund and account information For exchange transactions (subject to limitations) Toll-free, 24 hours a day, 7 days a week

Investor Information 800-662-7447 (SHIP) For fund and service information


(Text telephone for people with hearing impairment at 800-749-7273)	For literature requests Business hours only: Monday–Friday, 8 a.m. to 10 p.m., Eastern time; Saturday, 9 a.m. to 4 p.m., Eastern time
Client Services 800-662-2739 (CREW) (Text telephone for people with hearing impairment at 800-749-7273)	For account information For most account transactions Business hours only: Monday–Friday, 8 a.m. to 10 p.m., Eastern time; Saturday, 9 a.m. to 4 p.m., Eastern time
Admiral Services 888-237-9949	For Admiral account information For most Admiral transactions Business hours only: Monday–Friday, 8 a.m. to 10 p.m., Eastern time; Saturday, 9 a.m. to 4 p.m., Eastern time
Institutional Division 888-809-8102	For information and services for large institutional investors Business hours only: Monday–Friday, 8:30 a.m. to 9 p.m., Eastern time
Intermediary Sales Support 800-997-2798	For information and services for financial intermediaries including broker-dealers, trust institutions, insurance companies, and financial advisors Business hours only: Monday–Friday, 8:30 a.m. to 7 p.m., Eastern time

Glossary of Investment Terms

Capital Gains Distribution. Payment to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Cash Investments. Cash deposits, short-term bank deposits, and money market instruments that include U.S. Treasury bills and notes, bank certificates of deposit (CDs), repurchase agreements, commercial paper, and banker’s acceptances.

Common Stock. A security representing ownership rights in a corporation. A stockholder is entitled to share in the company’s profits, some of which may be paid out as dividends.

Dividend Distribution. Payment to mutual fund shareholders of income from interest or dividends generated by a fund’s investments.

Expense Ratio. The percentage of a fund’s average net assets used to pay its expenses during a fiscal year. The expense ratio includes management expenses—such as advisory fees, account maintenance, reporting, accounting, legal, and other administrative expenses—and any 12b-1 distribution fees. It does not include the transaction costs of buying and selling portfolio securities.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund’s investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is measured from the inception date.

Median Market Capitalization. An indicator of the size of companies in which a fund invests; the midpoint of market capitalization (market price x shares outstanding) of a fund’s stocks, weighted by the proportion of the fund’s assets invested in each stock. Stocks representing half of the fund’s assets have market capitalizations above the median, and the rest are below it.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investment vehicles.

Total Return. A percentage change, over a specified time period, in a mutual fund’s net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund’s volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment’s price.

P.O. Box 2600
Valley Forge, PA 19482-2600

Connect with Vanguard^®> www.vanguard.com

For More Information

If you would like more information about Vanguard Explorer Fund, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders

Additional information about the Fund’s investments is available in the Fund’s annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal year.

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Fund.

The SAI and portions of the current annual and semiannual reports are incorporated by reference into (and are thus legally a part of) this prospectus.

To receive a free copy of the latest annual or semiannual report or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit www.vanguard.com or contact us as follows:

The Vanguard Group

Investor Information Department P.O. Box 2600 Valley Forge, PA 19482-2600 Telephone: 800-662-7447 (SHIP)

Text telephone for people with hearing impairment: 800-749-7273

If you are a current Vanguard shareholder and would like information about your account, account transactions, and/or account statements, please call:

Client Services Department Telephone: 800-662-2739 (CREW)

Text telephone for people with hearing impairment: 800-749-7273

Information Provided by the Securities and Exchange Commission (SEC)

You can review and copy information about the Fund (including the SAI) at the SEC’s Public Reference Room in Washington, DC. To find out more about this public service, call the SEC at 202-551-8090. Reports and other information about the Fund are also available in the EDGAR database on the SEC’s Internet site at www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov, or by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-1520.

Fund’s Investment Company Act file number: 811-1530

Vanguard Marketing Corporation, Distributor.

P024 102010

Fund Summary

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.XX%
12b-1 Distribution Fee	None
Other Expenses	0.XX%
Total Annual Fund Operating Expenses	0.XX%

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 the same. 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
$XX	$XX	$XX	$XX

Portfolio Turnover

Primary Investment Strategies

Primary Risks

• 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.

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.

Annual Total Returns—Investor Shares¹

1 The year-to-date return as of the most recent calendar quarter, which ended on XXXX, was XXX%.

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%

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 or related services.

More on the Fund

in the securities markets. Look for this

symbol throughout the prospectus. It is

This prospectus offers the Fund‘s Investor Shares and is intended for participants in employer-sponsored retirement or savings plans. Another version—for investors who would like to open a personal investment account—can be obtained by calling Vanguard at 800-662-7447.

Plain Talk About Fund Expenses

All mutual funds have operating expenses. These expenses, which are deducted

from a fund’s gross income, are expressed as a percentage of the net assets of

the fund. Vanguard Explorer Fund Investor Shares’ expense ratio in fiscal year

2010 was 0.XX%, or $XXX per $1,000 of average net assets. The average

expense ratio for small-cap growth funds in 2009 was XXX%, or $XXX per $1,000

of average net assets (derived from data provided by Lipper Inc., which reports

on the mutual fund industry). Management expenses, which are one part of

operating expenses, include investment advisory fees as well as other costs of

managing a fund—such as account maintenance, reporting, accounting, legal,

and other administrative expenses.

Plain Talk About Costs of Investing

Costs are an important consideration in choosing a mutual fund. That’s because

you, as a shareholder, pay the costs of operating a fund, plus any transaction

costs incurred when the fund buys or sells securities. These costs can erode a

substantial portion of the gross income or the capital appreciation a fund

achieves. Even seemingly small differences in expenses can, over time, have a

dramatic effect on a fund’s performance.

Market Exposure

The Fund focuses on companies that are considered small-cap by the Fund’s advisors.


U.S. Stock Market Returns
(1926–2009)
	1 Year	5 Years	10 Years	20 Years
Best	54.2%	28.6%	19.9%	17.8%
Worst	–43.1	–12.4	–1.4	3.1
Average	11.8	10.1	10.7	11.3