Best Total Stock Market ETFs

A total stock market fund holds the entire investable US equity market, roughly 2,500 to 4,000 stocks spanning large, mid, and small caps. An S&P 500 fund, by contrast, holds only the largest 500 companies. The difference is the tail: total-market funds add the mid- and small-cap names that the S&P 500 excludes, which is about 10% to 20% of a total-market fund by weight.

That sounds like a meaningful gap, but it rarely is. Both kinds of fund are market-cap weighted, so the same mega-caps (Apple, Microsoft, Nvidia, Amazon, Alphabet) dominate the top of each. The S&P 500 already captures roughly 80% of total US market value, so the extra small-cap tail in a total-market fund moves the needle only at the margins. Over long periods, VTI and VOO have tracked closely. The practical read: a total-market fund gives you the most complete single-fund US exposure, and an S&P 500 fund gives you almost the same thing concentrated in the largest names.

VTI is the Vanguard Total Stock Market ETF and the most-held total-market fund, with hundreds of billions in assets. It tracks the CRSP US Total Market Index, holds several thousand US stocks, and costs about 0.03%. For most investors it is the reference point for “the whole US market in one ticker.”

ITOT, the iShares Core S&P Total US Stock Market ETF, is functionally the same product from BlackRock. It tracks an S&P total-market index rather than CRSP, but the holdings overlap almost entirely and the fee is the same roughly 0.03%. The two track each other so closely that the choice between them comes down to which fund family or fee-free brokerage you already use. If you want the deeper one-on-one breakdown, see the dedicated VTI and ITOT pages.

SCHB is the Schwab US Broad Market ETF, the Schwab version of the same idea. It tracks a Dow Jones US total-market index, holds the broad US market, and charges about 0.03%, matching VTI and ITOT. For someone who banks at Schwab, SCHB is the natural total-market core, and there is no meaningful performance reason to reach for one of the others.

Fidelity sells total-market exposure as mutual funds rather than ETFs. FSKAX, the Fidelity Total Market Index Fund, costs around 0.015%, even cheaper than the ETFs. FZROX, the Fidelity ZERO Total Market Index Fund, charges a 0% expense ratio, one of the only funds anywhere that costs nothing in annual fees. The trade-offs are mechanical: as mutual funds they trade once a day at the closing price (not intraday like an ETF), FZROX uses Fidelity's own proprietary index, and FZROX shares are not portable to other brokers. They are built to live inside a Fidelity account.

This is the question most people are really asking when they compare total-market funds to the S&P 500. The honest answer: the small-cap tail matters less than its size suggests. Because total-market funds are market-cap weighted, the small and mid caps that VTI adds over VOO sit at the bottom of the fund and carry little weight, while the same mega-caps drive both funds' returns.

Historically, small caps have sometimes outperformed and sometimes lagged large caps over multi-year stretches, which is exactly why a total-market fund and an S&P 500 fund drift apart only modestly. A total-market fund gives you a small, automatic stake in the next generation of companies as they grow up the size ladder, and it spares you from ever deciding to add a separate small-cap fund. An S&P 500 fund gives you a slightly more concentrated large-cap bet. Both are complete enough to be a single US core; the difference is breadth, not a performance edge in either direction. For a closer look at the S&P 500 side, see our best S&P 500 ETFs guide.

The unusual thing about total-market ETFs is how little separates the leaders. VTI, ITOT, and SCHB hold the same whole US market, several thousand stocks, at the same roughly 0.03%, and Fidelity's FSKAX and FZROX hold it for even less. Their long-run returns are within rounding error of each other because they own the identical underlying market. There is no “winner” in the performance sense.

So the decision is provider, not fund. Pick the version that matches the brokerage you already use: VTI at Vanguard, ITOT at an iShares-friendly or fee-free broker, SCHB at Schwab, FSKAX or FZROX at Fidelity. The only real wrinkles are mechanical: the ETFs (VTI, ITOT, SCHB) trade intraday and are portable between brokers, while the Fidelity mutual funds trade once a day and FZROX is locked to Fidelity. For more on weighing funds against each other, see how to compare ETFs.

Expense ratios are approximate as of early 2026; verify the current figure on each issuer's site. VTI, ITOT, and SCHB are exchange-traded funds; FSKAX and FZROX are Fidelity mutual funds (FZROX is the 0%-fee one). All five hold essentially the same whole US market, which is the central point: the table shows provider and cost, not five different markets.

Because the total-market funds are near-identical, the genuinely useful questions are about your own situation, not the funds in the abstract: which provider's version fits the account you already have, how much a total-market fund would overlap with stocks or ETFs you already hold (a lot, if you own large-cap US names), and how the broad US market has done against the S&P 500 over the window you care about. Those are questions an AI assistant can answer against your real holdings rather than a generic list.

That is where Walnut fits. It connects your existing brokerage through SnapTrade and lets you ask, in plain language through Claude, ChatGPT, or a built-in assistant, whether a total-market fund duplicates what you already own, which version suits your broker, and how each position is tracking the market. It is read-only by default, and you approve any trade. Walnut is not an investment adviser; it helps you see and act on your own portfolio rather than telling you what to buy.

A total stock market ETF is the most complete single-fund US core you can buy, and the leading versions are so alike that the choice is almost made for you. VTI, ITOT, and SCHB hold the same several-thousand-stock US market at about 0.03%; Fidelity's FSKAX and FZROX hold it for even less, with FZROX charging nothing. They are all broader than an S&P 500 fund like VOO, adding the mid- and small-cap tail that has historically moved long-run returns only at the margins. Pick on provider and account type, not on a performance ranking that does not really exist.

From a connected account you can dig into any of these as an ETF, look at an individual stock one of them holds, or read more on building a core in our best ETFs for beginners and best ETF in every category guides. Holdings, fees, and fund details change over time; treat the specifics here as a starting point and confirm on each provider's site before deciding.