It is not hidden away on the site. From the top menu under fees, there is a tab, interest earned. the policy is explained in full there. what trader_herry fails to address in his biased wikipedia piece is that IB's rates are much higher than most brokers and once you start hitting balances over 30K-50K, IB's rates more than cover the first 10K cost for most currencies and end up being a net advantage. I know in HK for example, we are offering much higher rates than the banks. if you're posting a low balance with us, you will feel the impact. If you post a larger balance, you'll reap the reward. herry, next time you make your statement, how about placing our interest earned in a table next to what other brokers pay in a table of 10,50 and 100K to show things in a fairer light. Another area not mentioned which is a much larger cost to many clients is margin interest. Our margin interest charges are as much as 3+% lower than many of the major brokerages. (herry, how about the same table for this one as well). In short, you need to look at the entire package to understand whether or not the other benefits and savings IB offers will compensate for this policy.