I've been trying to get IB to add a data column that includes the most recent cost to borrow the shares of stock. The rates can vary so much that it is very important to know before you enter into a trade. Please see a topic that I started many moons ago under their Features Poll. http://www.interactivebrokers.com/en/general/poll/poll.php?sid=3610 You can view the data yourself but it takes a good minute via Account Management. Please vote for the poll if you think it is important. Considering all the crap that has been added to the TWS it is shocking that they wouldn't add something like this.....
One is required to pay about 0.8% annual borrowing rate for holding it overnight. That's my definition of a hard to borrow stock. Check Account Management/Tools.