This is Tim Reynolds. He co-founded Jane Street Capital, which traded $17 trillion in securities in 2020. The result? Trading revenue of $10.6 billion by March 2021. Here's how they do it:

Jane Street makes money in ETF arbitrage and high-frequency trading. The firm ended 2020 having traded $4 trillion in global equities, $1.4 trillion in bonds, and $3.9 trillion in ETFs.