Are IB's margin requirements for futures normally higher than the exchange's? I must have missed something. When did this happen? CME's initial margin for ES = $4,758. IB's = $5,406.25.
A broker is allowed to enforce whatever margin they want. House rules. Don't forget the dotcom bubble era. Many brokers pretty much went to 100% maintenance margin overnight on all stocks when volatility kicked in.
Today I checked the IB margin to short 1 ES June 1860 put - it was $7110 which is more margin than being long 1 ES future. wtf