485BPOS

Securities Act of 1933 Registration No. 033-15983

Investment Company Act of 1940 Registration No. 811-05251

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 x

o Pre-Effective Amendment No.  ______

x Post-Effective Amendment No.  108

and

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940 x

x Amendment No.  108

Fidelity Concord Street Trust

 (Exact Name of Registrant as Specified in Charter)

245 Summer Street, Boston, Massachusetts 02210

(Address of Principal Executive Offices)(Zip Code)

Registrant’s Telephone Number: 617-563-7000

Marc Bryant, Secretary

245 Summer Street

Boston, Massachusetts 02210

(Name and Address of Agent for Service)

It is proposed that this filing will become effective immediately upon filing pursuant to paragraph (b) of Rule 485.

EXHIBIT INDEX

Exhibit	Exhibit No.
XBRL Instance Document	EX-101.INS
XBRL Taxonomy Extension Schema Document	EX-101.SCH
XBRL Taxonomy Extension Calculation Linkbase Document	EX-101.CAL
XBRL Taxonomy Extension Definition Linkbase Document	EX-101.DEF
XBRL Taxonomy Extension Labels Linkbase Document	EX-101.LAB
XBRL Taxonomy Extension Presentation Linkbase Document	EX-101.PRE

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for the effectiveness of this Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Post-Effective Amendment No. 108 to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Boston, and Commonwealth of Massachusetts, on the 4th day of September 2018.

	Fidelity Concord Street Trust
	By	/s/Stacie M. Smith
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||		Stacie M. Smith, President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

(Signature)		(Title)	(Date)
/s/Stacie M. Smith		President and Treasurer	September 4, 2018
Stacie M. Smith		(Principal Executive Officer)
/s/ John J. Burke III		Chief Financial Officer	September 4, 2018
John J. Burke III		(Principal Financial Officer)
/s/Jonathan Chiel	*	Trustee	September 4, 2018
Jonathan Chiel
/s/James C. Curvey	*	Trustee	September 4, 2018
James C. Curvey
/s/Dennis J. Dirks	*	Trustee	September 4, 2018
Dennis J. Dirks
/s/Donald F. Donahue	*	Trustee	September 4, 2018
Donald F. Donahue
/s/Alan J. Lacy	*	Trustee	September 4, 2018
Alan J. Lacy
/s/Ned C. Lautenbach	*	Trustee	September 4, 2018
Ned C. Lautenbach
/s/Joseph Mauriello	*	Trustee	September 4, 2018
Joseph Mauriello
/s/Charles S. Morrison	*	Trustee	September 4, 2018
Charles S. Morrison
/s/Cornelia M. Small	*	Trustee	September 4, 2018
Cornelia M. Small
/s/Garnett A. Smith	*	Trustee	September 4, 2018
Garnett A. Smith
/s/David M. Thomas	*	Trustee	September 4, 2018
David M. Thomas

*	By:	/s/Megan C. Johnson
		Megan C. Johnson, pursuant to powers of attorney dated March 2, 2018 and October 5, 2016 and filed herewith.

POWER OF ATTORNEY

I, the undersigned Trustee of the following investment companies:

Fidelity Advisor Series VIII Fidelity Concord Street Trust Fidelity Investment Trust Fidelity Puritan Trust Fidelity Securities Fund Variable Insurance Products Fund

in addition to any other Fidelity Fund for which the undersigned individual serves as Director or Trustee (collectively, the “Funds”), hereby constitute and appoint Thomas C. Bogle, Marc R. Bryant, John V. O’Hanlon, Robert W. Helm, Megan C. Johnson, and Anthony H. Zacharski, each of them singly, my true and lawful attorneys-in-fact, with full power of substitution, and with full power to each of them, to sign for me and in my name in the appropriate capacity, all Registration Statements of the Funds on Form N-1A, or any successors thereto, any and all subsequent Amendments, Pre-Effective Amendments, or Post-Effective Amendments to said Registration Statements or any successors thereto, and any supplements or other instruments in connection therewith, and generally to do all such things in my name and behalf in connection therewith as said attorneys-in-fact deem necessary or appropriate, to comply with the provisions of the Securities Act of 1933 and the Investment Company Act of 1940, and all related requirements of the

Securities and Exchange Commission.  I hereby ratify and confirm all that said attorneys-in-fact or their substitutes may do or cause to be done by virtue hereof.  This power of attorney is effective for all documents filed on or after October 5, 2016.

WITNESS my hand on this 5^th day of October, 2016.

/s/Jonathan Chiel

Jonathan Chiel

POWER OF ATTORNEY

We, the undersigned Directors or Trustees, as the case may be, of the following investment companies:

Fidelity Advisor Series I Fidelity Advisor Series VII Fidelity Advisor Series VIII Fidelity Beacon Street Trust Fidelity Capital Trust Fidelity Central Investment Portfolios LLC Fidelity Commonwealth Trust Fidelity Commonwealth Trust II Fidelity Concord Street Trust Fidelity Congress Street Fund Fidelity Contrafund Fidelity Covington Trust Fidelity Destiny Portfolios Fidelity Devonshire Trust Fidelity Exchange Fund Fidelity Financial Trust Fidelity Hanover Street Trust Fidelity Hastings Street Trust Fidelity Investment Trust Fidelity Magellan Fund Fidelity Mt. Vernon Street Trust Fidelity Puritan Trust Fidelity Securities Fund Fidelity Select Portfolios Fidelity Summer Street Trust Fidelity Trend Fund Variable Insurance Products Fund Variable Insurance Products Fund II Variable Insurance Products Fund III Variable Insurance Products Fund IV

in addition to any other investment company for which Fidelity Management & Research Company (“FMR”) or an affiliate acts as investment adviser and for which the undersigned individuals serve as Directors or Trustees (collectively, the “Funds”), hereby revoke all previous powers of attorney we have given to sign and otherwise act in our names and behalf in matters involving any investment company for which FMR or an affiliate acts as investment adviser and hereby constitute and appoint Thomas C. Bogle, John V. O’Hanlon, Robert W. Helm, Megan C. Johnson, and Anthony H. Zacharski, each of them singly, our true and lawful attorneys-in-fact, with full power of substitution, and with full power to each of them, to sign for us and in our names in the appropriate capacities, all Registration Statements of the Funds on Form N-1A, or any successors thereto, any and all subsequent Amendments, Pre-Effective Amendments, or Post-Effective Amendments to said Registration Statements or any successors thereto, and any supplements or other instruments in connection therewith, and generally to do all such things in our names and behalf in connection

therewith as said attorneys–in-fact deem necessary or appropriate, to comply with the provisions of the Securities Act of 1933 and the Investment Company Act of 1940, and all related requirements of the Securities and Exchange Commission.  We hereby ratify and confirm all that said attorneys-in-fact or their substitutes may do or cause to be done by virtue hereof.  This power of attorney is effective for all documents filed on or after March 2, 2018.

WITNESS our hands on this second day of March 2018.

/s/ James C. Curvey	/s/ Joseph Mauriello
James C. Curvey	Joseph Mauriello
/s/ Dennis J. Dirks	/s/ Charles S. Morrison
Dennis J. Dirks	Charles S. Morrison
/s/ Donald F. Donahue	/s/ Cornelia M. Small
Donald F. Donahue	Cornelia M. Small
/s/ Alan J. Lacy	/s/ Garnett A. Smith
Alan J. Lacy	Garnett A. Smith
/s/ Ned C. Lautenbach	/s/ David M. Thomas
Ned C. Lautenbach	David M. Thomas

XML

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Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Aug. 15, 2018
Registrant Name	dei_EntityRegistrantName	FIDELITY CONCORD STREET TRUST
Central Index Key	dei_EntityCentralIndexKey	0000819118
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Aug. 15, 2018
Document Effective Date	dei_DocumentEffectiveDate	Aug. 16, 2018
Prospectus Date	rr_ProspectusDate	Aug. 16, 2018

XML

Fidelity Series International Index Fund

Fund Summary

Fund:
Fidelity^® Series International Index Fund

Investment Objective

The fund seeks to provide investment results that correspond to the total return of foreign stock markets.

Fee Table

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund.

Shareholder fees
(fees paid directly from your investment)

Shareholder Fees	Fidelity Series International Index Fund Class: Fidelity Series International Index Fund USD ($)
Shareholder fees (fees paid directly from your investment)	none

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

Annual Operating Expenses	Fidelity Series International Index Fund Class: Fidelity Series International Index Fund
Management fee	none
Distribution and/or Service (12b-1) fees	none
Other expenses	0.36%	[1]
Total annual operating expenses	0.36%
Fee waiver and/or expense reimbursement	0.35%	[2]
Total annual operating expenses after fee waiver and/or expense reimbursement	0.01%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let’s say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here’s how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example	Fidelity Series International Index Fund Class: Fidelity Series International Index Fund USD ($)
1 year	$ 1
3 years	$ 3

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 operating expenses or in the example, affect the fund’s performance.

Principal Investment Strategies

• Normally investing at least 80% of assets in common stocks included in the MSCI EAFE Index, which represents that performance of foreign stock markets.

• Using statistical sampling techniques based on such factors as capitalization, industry exposures, dividend yield, price/earnings (P/E) ratio, price/book (P/B) ratio, earnings growth, and country weightings to attempt to replicate the returns of the MSCI EAFE Index.

• Lending securities to earn income for the fund.

Principal Investment Risks

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Foreign exchange rates also can be extremely volatile.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security’s or instrument’s value or result in delays in recovering securities and/or capital from a counterparty.

• Correlation to Index. The performance of the fund and its index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from its index.

• Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund’s index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund’s performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers.

• Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral.

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. You could lose money by investing in the fund.

Performance

Performance history will be available for the fund after the fund has been in operation for one calendar year.

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

[2] The Adviser has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, certain securities lending costs, brokerage commissions, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses, if any), as a percentage of its average net assets, exceed 0.014% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup prior reimbursed expenses up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through February 28, 2022. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	FIDELITY CONCORD STREET TRUST
Prospectus Date	rr_ProspectusDate	Aug. 16, 2018
Fidelity Series International Index Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summary Fund: Fidelity® Series International Index Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The fund seeks to provide investment results that correspond to the total return of foreign stock markets.
Expense [Heading]	rr_ExpenseHeading	Fee Table
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Operating Expenses (expenses that you pay each year as a % of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	February 28, 2022
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	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 operating expenses or in the example, affect the fund’s performance.
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Based on estimated amounts for the current fiscal year.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let’s say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here’s how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Normally investing at least 80% of assets in common stocks included in the MSCI EAFE Index, which represents that performance of foreign stock markets. Using statistical sampling techniques based on such factors as capitalization, industry exposures, dividend yield, price/earnings (P/E) ratio, price/book (P/B) ratio, earnings growth, and country weightings to attempt to replicate the returns of the MSCI EAFE Index. Lending securities to earn income for the fund.
Risk [Heading]	rr_RiskHeading	Principal Investment Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Foreign exchange rates also can be extremely volatile. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security’s or instrument’s value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from its index. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund’s index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund’s performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 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. You could lose money by investing in the fund.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money by investing in the fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Performance history will be available for the fund after the fund has been in operation for one calendar year.
Fidelity Series International Index Fund | Class: Fidelity Series International Index Fund
Risk/Return:	rr_RiskReturnAbstract
Shareholder fees (fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management fee	rr_ManagementFeesOverAssets	none
Distribution and/or Service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.36%	[1]
Total annual operating expenses	rr_ExpensesOverAssets	0.36%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.35%	[2]
Total annual operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	0.01%
1 year	rr_ExpenseExampleYear01	$ 1
3 years	rr_ExpenseExampleYear03	$ 3

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

[2] The Adviser has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, certain securities lending costs, brokerage commissions, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses, if any), as a percentage of its average net assets, exceed 0.014% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup prior reimbursed expenses up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through February 28, 2022. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	FIDELITY CONCORD STREET TRUST
Prospectus Date	rr_ProspectusDate	Aug. 16, 2018
Document Creation Date	dei_DocumentCreationDate	Aug. 15, 2018