I am interested to hear if anyone has noticed significant differences in margin treatment at various brokers. As an example, one stock I was trading recently ($350M market cap) had initial margin requirements of: 100% at IB 70% at TD Ameritrade 50% at many other brokers who didn't have any stock-specific rules I don't have portfolio margin at TDA, not sure if that would have helped more. It was definitely a lot more capital efficient to use other brokers, even though I could get better execution/costs at IB. Of course it turns out writing puts was the most capital efficient of all (expired worthless yesterday), but there wasn't much liquidity for that. If there are any general trends in terms of which brokers are better for midcap/small cap equities, I'd be happy to hear them. IB has been generally pretty strict on lots of smaller cap stuff over the recent years, with most now 100% requirements.
It would help to know the stock symbol. Yes, many brokers offer different leverage on some securities. A typical reason for this might be, low volume, high volatility, concentrated portfolios, new issue or small cap. 1245