I am analyzing some futures brokers in china and HK, I see that "interest income" consists of a high % of total revenue.
For a comprehensive broker like InteractiveBloke, thats understandable as they provide margin financing.
I believe futures brokers don't provide margin financing as futures are leveraged by design.
The Chinese futures brokers get paid 2% interest on their clients' margin deposits with the clearing firm, then they pass on 0% to the clients, pocketing it all.
I think there are two sources of interest income. 1. the clients' money deposited with clearing firm which earns interest, 2. the excess clients' money deposited in banks or money market securities that pay interest. Does 1 exist in US? Also, I believe by regulation brokers are required to pay interest on clients' cash?