When you give something away free, people are probably going to want more of it. That is the experience so far for online brokers following the industrywide move to zero-commission trading in October. Investors initially punished the companies for vaporizing a big chunk of their revenue but wised up when they began to consider the bigger picture. More people trading means more cheap cash that can generate other revenue, plus bigger opportunities to sell services like wealth management or automated portfolio tools.

Source: Wall Street Journal January 24, 2020 12:00 UTC