Major Total Market Indices

At a Glance

Security counts are approximate and fluctuate as companies IPO, merge, or are delisted. Data current as of April 2026.

CRSP US Total Market Index

The CRSP US Total Market Index is maintained by the Center for Research in Security Prices at the University of Chicago Booth School of Business — one of the oldest and most respected financial data repositories in the world. CRSP has maintained US equity data since 1926.

The index uses market-capitalisation bands to define its size segments rather than fixed cutoff counts. This approach reduces unnecessary index turnover at size-segment boundaries: a company doesn't leave the index because it crossed an arbitrary rank threshold, only because its market cap fell below the index's minimum investable threshold. The result is a lower-turnover, lower-cost index to replicate.

The CRSP US Total Market Index became the most widely tracked total market benchmark when Vanguard switched from the Wilshire 5000 to CRSP in 2012 — bringing VTI and VTSAX (combined AUM exceeding $1.8 trillion) under its methodology.

Major funds tracking this index

• Vanguard Total Stock Market ETF (VTI) — 0.03% expense ratio
• Vanguard Total Stock Market Index Fund Admiral Shares (VTSAX) — 0.04%
• Fidelity Total Market Index Fund (FSKAX) — 0.015%
• Schwab Total Stock Market Index Fund (SWTSX) — 0.03%

Russell 3000 Index

The Russell 3000 ranks all eligible US stocks by total market capitalisation and selects the top 3,000. It was introduced in 1984 as the definitive benchmark for the broad US equity market, and it remains the preferred benchmark for institutional investors and active managers who want to measure performance against a comprehensive market proxy.

A key characteristic of the Russell methodology is its annual reconstitution in late June — a scheduled event that generates significant market activity as index funds tracking the Russell indices rebalance simultaneously. Stocks that cross the threshold between the Russell 2000 (small-cap) and Russell 1000 (large-cap) components attract substantial trading volumes around reconstitution.

The annual rebalancing schedule means the Russell 3000 may be slower to reflect changes in the market — new IPOs are not added until the next annual reconstitution unless special eligibility criteria are met.

Sub-indices

The Russell 3000 is composed of two widely followed sub-indices:

• Russell 1000 — the top 1,000 companies by market cap (~92% of US market cap)
• Russell 2000 — the next 2,000 companies (~8% of US market cap). The most widely traded small-cap benchmark in the world.

Major funds tracking this index

• iShares Russell 3000 ETF (IWV) — 0.20% expense ratio
• Vanguard Russell 3000 ETF (VTHR) — 0.10%

Wilshire 5000 Total Market Index

The Wilshire 5000 is the original total market index — the first benchmark ever created to measure the performance of all publicly traded US stocks. Wilshire Associates launched it on December 14, 1974, named for the approximately 5,000 companies it originally tracked.

The name has become a historical misnomer: the number of US public companies has declined significantly since 1974 due to corporate mergers, acquisitions, delistings, and a long-term trend of fewer companies choosing to go public. The Wilshire 5000 today tracks approximately 3,500 securities — fewer than its name implies, but still covering the entire investable US equity universe.

The Wilshire 5000 served as the underlying index for the Vanguard Total Stock Market Index Fund from its 1992 launch until 2012, when Vanguard switched to the CRSP index. The Wilshire 5000 now has limited retail fund coverage but remains the authoritative historical benchmark for long-term US market performance studies dating back to 1974.

Major funds tracking this index

• Wilshire 5000 Index Fund (WFIVX) — 0.50% expense ratio

S&P Total Market Index

The S&P Total Market Index was created by S&P Dow Jones Indices — the same organisation that maintains the S&P 500 — to provide a comprehensive US equity benchmark that extends beyond the 500-stock flagship. It covers large, mid, small, and micro-cap US equities.

The S&P Total Market Index uses the same eligibility criteria and float-adjustment methodology as the S&P 500, applied across the full market. This means it is fully consistent with the S&P 500: the S&P 500 is a strict subset of the S&P Total Market Index.

Despite its comprehensive coverage, the S&P Total Market Index has attracted less retail fund tracking than CRSP or Russell 3000. It is used primarily as an institutional benchmark.

MSCI USA Investable Market Index (IMI)

The MSCI USA Investable Market Index is MSCI's total market equivalent for the United States, covering large-cap, mid-cap, and small-cap stocks. It is part of MSCI's global IMI framework, which allows consistent total market measurement across countries and regions.

The MSCI IMI methodology defines large and mid-cap stocks as the top 85% of each market's float-adjusted capitalisation, and small-cap stocks as the next 14%, for a combined coverage of approximately 99%. The bottom 1% (micro-caps below minimum investability thresholds) is excluded.

The MSCI USA IMI is primarily used as a benchmark by institutional investors — particularly those managing global or international portfolios who need a US component that is methodologically consistent with MSCI's non-US indices (such as the MSCI ACWI IMI or MSCI World IMI).

Related global indices

• MSCI ACWI IMI — All Country World, covering 23 developed + 24 emerging markets, ~9,000 securities
• MSCI World IMI — 23 developed markets only, ~6,000 securities