They're nearly the same thing in the hedge fund's case. Most of them take some variant of 2&20 still, so 20% of fund profits is their revenue.
They don't need much capital, and I'd say that many have no outside investors. So, their trading PnL minus cost of running the operation is the net profit.
On the other hand, the trading PnL will typically be a tiny part of their total trading volume (maybe a few bp).