History
The Total Market Portfolio is closely associated with the rise of broad-market indexing led by Vanguard in the 1970s and 1980s. While early index funds tracked narrower benchmarks such as the S&P 500, later innovations expanded coverage to include the entire investable market, including mid-cap and small-cap stocks. In the United States, this led to the creation of total market indices such as the CRSP US Total Market Index (used by Vanguard) and the Dow Jones US Total Stock Market Index. These indices aim to capture nearly 100% of the investable equity universe by including companies across the full size spectrum. The result is a more complete representation of the domestic economy than large-cap-only benchmarks.
Philosophy
The Total Market Portfolio applies the core indexing idea at the country level: instead of selecting sectors, styles or individual stocks, the investor owns the entire market. Market-cap weighting ensures that larger companies receive more weight, while still including smaller firms that contribute to long-term growth and factor exposure. The approach avoids the need to decide between large-cap, mid-cap or small-cap allocations, collapsing all of them into a single fund. The strength is completeness and simplicity. The limitation is concentration in the domestic market and lack of international diversification, which makes the portfolio sensitive to country-specific risks.