I checked the contract search on the site and it said it is not shortable. However, when i try it on the paper account, it can be shorted. Does anyone has experience shorting the SPY thru IB? I am asking this because i dont want to see an opportunity and then have more order rejected. Also, Steve said shorting HK ETF has a lot of extra cost ( like borrowing fees, regulation fees) . Is it also the case with the SPY or does the $1 / 100 shares commision has included all the fees?