According to Eric Balchunas, the debate between investing in the S&P 500 Index (SPX) versus the Total Market Index (such as VTI) centers on the concentration of large-cap stocks and breadth of market exposure. SPX is favored by more investors due to its focus on major US companies, many of which now IPO as large caps, reducing the incremental value of broader market coverage. For crypto traders, this trend indicates that institutional capital may continue to favor established, high-liquidity assets, which could influence risk appetite and cross-market flows, especially as both equity and crypto markets see increased overlap in investor profiles and ETF adoption. Source: Eric Balchunas on Twitter, May 20, 2025.