I apologize in advance for what is probably a very simple question, but: Can anyone outline the costs involved in borrowing stock (ie, to enter a <b>short</b> position) on margin using a plain old Reg-T margin account? Obviously there's the margin interest rate, but is there also a separate 'short stock borrow' cost as well? I ask because while I'm familiar enough with the idea of borrowing money from my broker to enter a <b>long</b> position using margin, and the annual interest rates associated with that borrowing, I'm not so clear on what I pay in interests/fees for entering a short position on margin. Is it just the usual margin rate, or does the 'indicative rate' of which I'm reading imply some extra cost? Again, apologies for what's probably a very simple question, but I'm relatively new to this and want to understand my costs before entering any short transactions of this sort. As an example, assume I have $10K in my account, and want to short $15K worth of XYZ Corp. My hypothetical broker's current margin interest rate is 5%. Thanks for any help anyone can provide.