What is just payment from investor to trader

I gained usd1550 in a month for the investor. What is the right payment for the trader? 40%?

The split is usually 20 to 30% for the Trader. (I usually take 25%)

there is no rule about. I work with institutional investor which pays 75% plus boni to the trader
From privat investor I take usually 25-50%, depends on the acc. size, the bigger, the less %