If you've been an investor for any length of time at all, then you've almost certainly been advised to start (and maybe even finish) with index funds like the Vanguard S&P 500 ETF. This fund is of course simply meant to mirror the performance of the S&P 500.

If you're new to investing and don't have a lot of money to get started, don't fret. The best place for new investors to begin is often with exchange-traded funds (ETFs), which will give investors instant diversification through a portfolio of stock holdings.

As market-capitalization-weighted index ETFs, both VOO and VTI naturally feature a high allocation to large-cap stocks. If you want to focus more on mid- and small-cap stocks, a dedicated non-core ETF like VXF might be ideal. This ETF tracks the S&P Completion Index for a 0.06% expense ratio.

The Vanguard Total Stock Market ETF's comprehensive coverage makes it an ideal foundation for long-term investing strategies. Its broad diversification across all market segments eliminates the need to hold multiple equity funds, simplifying portfolio management and reducing overall costs.

Vanguard is one of the gold standards when it comes to low-cost exchange-traded fund (ETF) options. Undoubtedly, passive investing (typically with index funds) tends to be wildly popular among the retail crowd.