Investing in the S&P Total Market Index: ETFs and US Portfolio Guide

ETF Vehicles That Track This Index

ITOT (iShares Core S&P U.S. Stock Market ETF) is the primary ETF tracking the S&P Total Market Index. Managed by BlackRock's iShares unit, ITOT holds over 2,600 US-listed stocks across all market capitalizations at an expense ratio of 0.03 percent. It is commission-free at Fidelity and many other brokerage platforms that participate in the iShares commission-free program.

The S&P Total Market Index is sometimes compared to the Dow Jones US Total Stock Market Index, which underlies SCHB (Schwab US Broad Market ETF). Both charge 0.03 percent and cover a broad swath of US equity, but they are different indexes maintained by the same parent company (S&P Dow Jones Indices). SCHB holds roughly 2,500 stocks, while ITOT holds over 2,600. The coverage difference reflects methodological choices in each index rather than a meaningful quality distinction.

The most common comparison investors make is ITOT versus VTI (Vanguard Total Stock Market ETF). VTI tracks the CRSP US Total Market Index, which covers over 3,800 stocks including very small micro-cap companies that neither ITOT nor SCHB holds in large quantity. Both ITOT and VTI charge 0.03 percent and have produced nearly identical long-run returns. For most investors, the choice between them comes down to brokerage preference, trading costs, or whether they already hold one in a tax-advantaged account.

Expense Ratios and Costs

ITOT's 0.03 percent annual expense ratio matches the lowest-cost S&P 500 ETFs such as IVV and VOO. An investor holding $50,000 in ITOT pays $15 per year in management fees. This fee level has remained stable for several years and reflects the competitive pressure among iShares, Vanguard, and Schwab in the broad US equity ETF category.

There is no cost penalty for buying total-market breadth over S&P 500-only coverage. ITOT provides thousands of additional small and micro-cap holdings at the same fee as a pure large-cap S&P 500 fund. Investors who previously held separate large-cap and small-cap ETFs can consolidate into ITOT without paying more and often pay less by eliminating one fund's expense ratio and simplifying rebalancing.

Trading costs beyond the expense ratio are worth noting. ITOT has substantial daily trading volume and tight bid-ask spreads, but SPY and IVV trade with even tighter spreads due to their larger asset bases and institutional liquidity. For individual investors making purchases in the hundreds or thousands of dollars, the difference in bid-ask spread is negligible. For institutional-scale trades, the spread difference could matter and IVV may be preferred for very large transactions before holding ITOT long-term.

Portfolio Role and Benchmarking

For investors building a simple, broadly diversified US equity portfolio, ITOT or VTI serve as the most suitable single-fund core holding. A portfolio consisting solely of ITOT plus a broad international ETF (such as VXUS) represents the entire global equity market in two funds. Adding a bond ETF creates a three-fund portfolio covering the full investable universe at low cost and with minimal complexity.

The S&P Total Market Index is less commonly cited as an institutional benchmark than the Russell 3000, which remains the dominant institutional US total market reference. Advisers benchmarking client portfolios against a published index tend to use Russell 3000 or S&P 500 rather than the S&P Total Market. For individual investors, this distinction is immaterial because the investment objective is return rather than benchmark tracking, and ITOT's performance closely follows all three indexes over long periods.

The absence of a quality screen is the key structural difference between ITOT and SPTM. ITOT includes unprofitable companies that fail to meet S&P's earnings criteria, while SPTM and the S&P Composite 1500 exclude them. Whether this quality screen adds or detracts from returns depends on the market environment. Investors who want the broadest possible exposure and accept that some holdings will be unprofitable companies should prefer ITOT. Investors who want the quality filter built into the index construction should consider SPTM instead.

Tax Considerations for US Investors

ITOT shares the core tax advantage of all ETFs: the creation and redemption mechanism allows authorized participants to exchange ETF shares for baskets of underlying stocks, enabling the fund to remove low-cost-basis positions without triggering capital gain distributions to shareholders. ITOT has historically distributed little to no capital gains, consistent with broad-market ETFs at this expense level.

Broad diversification across 2,600+ stocks creates more potential tax-loss harvesting candidates within a taxable account compared to a concentrated fund. Individual positions in ITOT may show unrealized losses at any given time even when the overall portfolio is positive, creating opportunities to realize losses in specific lots through selective share identification (specific identification cost basis method).

The most notable tax feature of ITOT for individual investors is its relationship to VTI for tax-loss harvesting purposes. Because ITOT (S&P Total Market Index) and VTI (CRSP US Total Market Index) track different indexes maintained by separate methodologies, they are generally treated as substantially different securities under the wash-sale rule. An investor who sells ITOT at a loss and immediately buys VTI can realize the tax loss while maintaining near-identical market exposure without a wash-sale disallowance. The IRS has not issued definitive guidance on whether these two specific funds are substantially identical, so investors should confirm this interpretation with a tax adviser before executing the strategy. SCHB (Dow Jones US Broad Stock Market) serves as a third rotation option in the same tax-loss harvesting pair.

Dividend income from ITOT consists primarily of qualified dividends because most holdings are large and mid-cap US corporations that pay ordinary dividends on common stock. Small and micro-cap holdings may pay fewer dividends on average, but their weight in the market-cap-weighted index is small enough that the qualified dividend composition closely resembles the S&P 500's profile.