> Binance did $40 billion in volume in the last 24 hours.

It didn't

> Even if their effective fee is only 1/100 of a percent that's $4 million.

It's not.

The reason? They "traded" fictitious currencies whose "value" is pure speculation and nonsense. Their fees are also denominated in these fictitious currencies.

However, neither the offices they rent nor the people they employ have any interest in these, because rent and salaries are paid in something that actually has value: the dollar.

Now, where does the actual money come from is a good question, but I'm too lazy to read their SEC filing.