Investors benchmark their performance against a standard or index with comparable investments. The benchmark differs depending on the investments, the desired strategy, and the preferred outcome.
ETFs and mutual funds charge management fees to keep the lights on and pay employees. They determine these fees using an expense ratio, a percentage of the AUM.
Passive investing is a long-term investing strategy where investors buy and hold a diversified mix of investments to match the market's performance. Unlike active investors, passive investors do not try to "beat the market"; they want their portfolio to look like the market.