Ten years ago, IB had a superior platform. These days I think most of the internal operations of the bigger banks - and even some smaller brokers - have caught up to the technology.
IB was literally hours away from buying MF Global.
http://finance.fortune.cnn.com/2012/06/04/the-last-days-of-mf-global/
freedinner posted this link in another thread and it's a great read. TP was putting up 800mm of his own money to take MF Global, but when they discovered that the books were in serious disarray, he was smart enough to step away. It shows that he is looking for opportunities - at least on the acquisition side.
I think you have to look at why IB would be attractive to a buyer.
From what I understand, the customer base isn't that great. TP wanted to buy MFG to get their seg account base. So why hasn't IB grown much more organically with their great technology and low prices? I think that's what these potential suitors have to look at. When I became a customer many years ago, I thought IB would blow everyone away.
Customer service is anywhere from good to comically inept, with the majority of interactions favoring the latter - and I'm on the pro side. The auto-liquidate does a great job of protecting IB and the customer (often from themselves), however there are still notable issues with wrongful auto liquidations of accounts that have been misvalued during fast or thin markets. IB's general response - "too bad". You can't grow the business when you keep doing that to the people that are leaving significant funds in your custody and generating tons of commission.
I don't see a great reason to be a buyer of IB. What would the buyer be looking to gain from the deal?