$65M penalty for $35M in misbehavior. That is how you get Wall Street to pay attention. More like this please!
You'd need better than 50-50 odds. ;)
0.5 * -65M + 1 * 34M = +1.5M
They get the +34M 100% of the time, not 50%, they didn't have to surrender it.
So Robinhood took money from its customers to this extent: all the cash as if its customers were paying commissions, and also $34M, and for that they're being fined $65M, which will probably be negotiated down to $2M or something like that.
This might make sense: if users were knowledgeable and had multiple brokers, they may execute at the better trade-specific broker for each trade, so adding up just the potential bads gives some perspective. But on the other hand, it's not a perfect indicator for Robinhood's net gain as its omitting trades where Robinhood's structure leads to lower commission.