Firstly, this isn't true. Just this week AMC was trading tens of billions of dollars worth of shares per day, which is about equal to AAPL. GME is seeing >twice

Firstly, this isn't true. Just this week AMC was trading tens of billions of dollars worth of shares per day, which is about equal to AAPL. GME is seeing >twice as much. Second, the insane amount of volatility and concentration in these tickers makes the clearinghouses charge the brokerages way way more. You have fees (quoted in %) for expected change and also lack of diversity.