A couple of questions:
What do you mean by high margin in IB? Do you mean margin interest rate is high in IB compared to Fidelity? !!!. Actually it is lower and it is over 5% lower. Please elaborate because my blood started to boil when I read your statement as I have used both and many other brokers.
Do you believe Fidelity's platform is better than IB's platform? Sorry I can not even compare them It is like comparing Lexus with a cheap car. Even Fidelity active trader pro is sub par to IB. Many traders that use IB platform are not familiar with bells and whistles of TWS.
I hope you make a decision that makes sense and makes you happy but I was shocked with your statements. Can you trade between 4PM and 4:15 PM ET in Fildeity? The answer is no. Call them up and ask them why. Ask them can you put an order which is true for the regular hours and after hours? the answer is NO.
Well first, we are just discussing some brokers who take our money so no need for blood to boil. LOL Anyway, moving onto IB...
When I mean margin, I am referring to the leverage that IB requires for trading for both Futures and Forex, they are high and not competitive at all comparing to other FCM and other brokers. Its DAY margin on Euro FX Futures for example is $4825!!!! That's FOUR times more than any futures brokers out there charges. Forget about the other popular futures contract like CL, GC, you won't be able to trade them unless you have at least #20K in the account. And even its day margin on E-mini SP 500, the most liquid Futures contract traded is still high comparing to other brokers. In Forex, its margin is 33:1 on MAJORS, that is the HIGHEST in all brokers in the Forex industry. The SEC from US imposed a maximum leverage cap of 50:1 to all Forex products and that is already the lowest among all the regulated countries but IB's leverage is 33:1 !!
Second, regarding TWS, even with its bells and whistles that the software may offer, in my experience, it's still badly designed software that is horribly outdated which results in extremely slow performance at times and very prone to errors. What is even more concerning is that when you report these problems to the technical support, they completely ignore you; they either deny it pretending it doesn't exist or ridicule you the clients let alone do anything about it. On top of that, IB is the ONLY broker that I know that does NOT offer a decent charting facility. For the longest time, all you have is a clumsy, clunky and completely inaccurate charts that plots midpoints of price. Who, in this day 'n' age plots "midpoints" on a chart for trading?? IB's new charting software from MultiCharts is an improvement but still it still has a long learning curve and many of the indicators are still either missing or not properly programmed. And if you want to use MultiCharts to trade, you have to pay each month.
Oh and btw, you cannot trade from 4:00 pm to 4:15 pm either on IB. It's their daily maintenance. And not only that, if you trade forex, you cannot trade the kiwi from 3:00 to 3:15 pm either. And IB is the ONLY broker in the forex industry that does this and it's absolutely ridiculous and inconvenient and risky. Anything can happen within these 15-min. period and you cannot do anything about it. They claim first it's compliance to regulatory requirement from the New Zealand exchange which is totally not true and is utter BS. There is absolutely no such requirement from the New Zealand financial authority anywhere and then when I probed more, no customer service can tell you an answer for sure. I later found out it's because IB is trying to sync the spot forex with the trading of the kiwi futures and somehow the kiwi futures has a trading halt from 3:00 to 3:15 pm something like that. WHY? They want to do that? I have absolutely no idea and nothing published from IB ever explains it. Like I said, NO any other brokers around the world in the forex industry has this "trading halt" on the kiwi and they are fine so obviously this is not needed. But the fact that they don't even properly explains to their own employees and their clients what that "trading halt" is all about is just appalling.
Their swap rate, or roll-over interest rate on Forex currency is horrible, the LOWEST among all brokers.
Like I said, the ONLY thing positive about IB is its execution, slippage, and the fast processing your withdrawal requests. Besides these, there is nothing else. Glad I left there because comparing to IB, any broker is a + and I am sure Fidelity would be too.