VTI tracks the CRSP US Total Market Index, covering essentially every investable US publicly traded company — approximately 3,600 stocks from mega-caps to micro-caps — weighted by market capitalization. With $2 trillion in assets, it is the largest ETF in the world. The top holdings are identical to any US cap-weighted index — Apple, Microsoft, NVIDIA, Amazon and Alphabet dominate since cap-weighting allocates most of the fund to the largest companies. The practical difference between VTI and VOO is the additional small and mid-cap exposure: VTI includes roughly 1,500 additional companies beyond the S&P 500, which represents a small fraction of total assets given their market cap but adds genuine diversification. At 0.03%, VTI is as cheap as investing gets. John Bogle's vision of the total market index as the optimal equity vehicle for most investors is embodied in VTI — low cost, complete diversification, no manager risk, no rebalancing required. For investors, VTI is alongside VOO as the foundational equity building block of any long-term portfolio. The choice between VTI and VOO comes down to whether the broader small and mid-cap coverage of VTI is valued — for most investors it makes a negligible difference in long-term outcomes, and either fund serves as an excellent core equity holding.
