[ayamaguc]

IMO they would be considered either rebates or gifts, neither of which is taxable. Having to choose one or the other, I would say rebate. Again, not taxable.

I would be careful here. The sense I have gathered and my personal conclusion is that these are in fact taxable. They are income and must be declared.

The analogue currently in my head relates to brokerage transactions involving a commission. When you make a trade the brokerage tacks on a commission which you pay, which is added to your cost basis and reduces your profit when you close your position (or increases your loss if you're taking one). Thus you're already getting a deduction of the commission from your gains. You don't get it twice if you get a commission rebate. Either your basis is reduced so your profit greater (and hence taxex) or your basis remains the same but you're receiving income (and hence taxed).

Rakeback and bonuses are like getting a commission rebate.

But that's just my amateur conclusion.