Institutional Investors' Performances Compared to the Markets Interest Rates Affect Almost Everything in Economics

Interest on Your Brokerage Accounts

You are likely to always have some cash in your brokerage account. Some brokerages will offer 3-5% interest on this money, while others won't offer you a thing. Phone or email the brokerage to find out what they offer. In fact, this is a good question to ask their customer service!
Source: http://www.investopedia.com/articles/00/112100.asp