Whats the highest bonuses for investing with brokerages with less than 5k. (fidelity for example offers $100 if u invest $50)

I am quite low on funds but have about 5k and I want to invest in investo qqq or spxl. Something like 3x leverage on the market. I saw an offer from fidelity that gives $100 when you invest $50. I want to invest at least $500 minimum so I was wondering if there were any other higher bonuses for higher amounts. Do y'all know any?