The domestic broad-market ETF sector is highly competitive, with popular options like Vanguard's and iShares' total market and S&P 500 funds. While these funds offer low costs, blended styles, and broad sector coverage, there are lesser-known alternatives worth considering. 

For broad U.S. market exposure, the Schwab U.S. Broad Market ETF (SCHB) and the SPDR Portfolio S&P 1500 Composite Stock Market ETF (SPTM) provide similar market coverage at lower costs. For those focused on large-cap exposure, the SPDR Portfolio S&P 500 ETF (SPLG) and BNY Mellon US Large Cap Core Equity ETF (BKLC) offer even lower expense ratios. 

Using these alternatives can enhance tax-loss harvesting strategies while maintaining market exposure. By diversifying beyond the usual Vanguard and iShares funds, investors may find cost savings and strategic benefits.

Finsum: You can still implement thematic investing with these ETFs, so keep this in mind when making decisions.