FSKAX — Fidelity Total Market Index Fund
What FSKAX holds, how it works, who it fits, and how it compares
FSKAX is the ticker for Fidelity Total Market Index Fund, an index mutual fund from Fidelity built to follow the entire U.S. stock market. This page walks through what the fund actually holds, how its index works, who tends to use it, how it stacks up against VTSAX and other lookalikes, and the mechanics of buying it. Everything here is educational — none of it is a recommendation to buy or sell.
What FSKAX is
Buying FSKAX means buying a share of a pooled fund that owns, or closely mirrors, a basket of securities defined by published index rules. You are not picking individual companies and the fund manager is not either — the index decides what goes in and how much of it.
FSKAX is Fidelity’s answer to VTSAX: the entire U.S. stock market in one mutual fund, with no minimum investment and a very low expense ratio. It frequently shows up as the broad-market option in Fidelity accounts and some employer plans.
Fidelity also markets a zero-expense-ratio total market fund. It is cheaper on paper but uses a proprietary in-house index and is even less portable, which is a trade-off worth understanding before choosing it over FSKAX.
- Issuer: Fidelity
- Tracks: the entire U.S. stock market
- Style shorthand: total U.S. stock market
- Wrapper: an index mutual fund, so orders fill once a day at the closing net asset value
- Typical role in a portfolio: a single-fund U.S. equity core
How FSKAX works
An index is a published list of securities plus a rule for how much of each to hold. FSKAX aims to match that list closely enough that its results resemble the index minus costs. Small gaps between the two — tracking difference — come from fees, cash held between trades, and the practical cost of buying thinly traded positions.
The fund tracks a Dow Jones U.S. total stock market index rather than the CRSP index Vanguard uses. Both aim to represent the investable U.S. market, and the methodological differences are small enough that results have tracked closely.
Holdings run into the thousands, priced once a day at NAV. Because index turnover is low and the fund is large, the operational costs of maintaining that many positions are spread thin.
As a mutual fund, FSKAX does not trade during the day. You submit an order in dollars or shares and it fills at the net asset value struck after the close. There is no bid-ask spread and no premium or discount to worry about, but there is also no way to react to an intraday move — which for long-term investors is closer to a benefit than a limitation.
Costs come in two flavors. The expense ratio is the annual fee skimmed from assets, quoted as a percentage and deducted continuously rather than billed. Then there are transaction frictions: bid-ask spreads and any commissions for ETFs, minimum investments and potential short-term redemption rules for mutual funds. Low cost is a real advantage, but it is one input among several rather than the whole decision.
Who FSKAX is for
FSKAX provides total U.S. stock market exposure through Fidelity. Whether that belongs in your portfolio depends on your time horizon, what you already own, which accounts you have available, and how you behave when markets drop — not on how often the ticker appears in headlines.
FSKAX suits Fidelity customers who want total-market exposure and the ability to start with any dollar amount. It slots directly into a three-fund portfolio built entirely within one brokerage.
It carries the same portability caveat as other proprietary mutual funds: you generally cannot transfer it in kind to a different firm. In a taxable account, that could mean realizing gains if you ever leave Fidelity.
Three questions are worth answering before you decide. What specific job would this holding do — growth, ballast, income, or geographic diversification? How long can the money stay invested without being touched? And what do you already own that covers the same ground?
FSKAX vs peers
The funds most often mentioned alongside FSKAX are VTSAX (Vanguard Total Stock Market Index Fund Admiral Shares), SWTSX (Schwab Total Stock Market Index Fund). The useful question is not which one is “best” in the abstract, but which small differences actually matter for what you are trying to do.
Against VTSAX, the meaningful differences are the minimum investment, the index provider, and which brokerage you are committing to. Holdings overlap almost completely.
Against SWTSX, the comparison is nearly symmetric — another no-minimum, low-cost total market fund tied to another brokerage. Consolidating at whichever firm holds the rest of your money usually beats optimizing the last basis point.
When you compare any two funds in this category, look at index methodology first — what is included and excluded, and how holdings are weighted. Then compare the expense ratio, the minimum investment, liquidity and spreads for ETFs, tax treatment in the account you plan to use, and whether you can move the position to another brokerage without selling it.
How to buy FSKAX
Once you have an account that offers it, purchasing FSKAX is mechanical. The steps below are educational and describe the process, not a suggestion that you should take it.
- Confirm the fund is available in your brokerage account or employer plan menu.
- Search ticker FSKAX and read the prospectus and share-class details.
- Check the minimum initial investment for the share class, and whether a lower-minimum class or ETF equivalent exists.
- Enter a dollar amount rather than a share count — mutual funds handle fractional shares automatically and your full contribution gets invested.
- Set up an automatic recurring purchase if consistency is your weak point, then leave it alone.
If your Fidelity 401(k) offers an S&P 500 fund but not a total market fund, holding FSKAX in an IRA is one way to add the mid- and small-cap slice without fighting your plan menu.
Before you place the order, make sure the money is genuinely long-term. Keep an emergency fund in cash separately, know how this position overlaps with what you already hold, and have a rough plan for what you will do the first time it drops twenty percent — because at some point it will.