Comment by pushrax

Proper brokerages will pay you to lend your securities, transparently disclose their programs, and require consent. For example:

- https://www.interactivebrokers.com/en/pricing/stock-yield-en...

- https://www.fidelity.com/trading/fully-paid-lending

Some brokerages lend out spare cash (and pay a transparent interest rate, and are subject to strict reserve requirements) but the majority of assets controlled by a typical brokerage are securities. FTX assets were all subject to their leverage strategies, with no specific reserve.