BioAmber Inc fka BIOAQ

[trader59]

He's telling you that you have to have a margin account with your broker in order to short stocks, and in particular penny stocks. $2.50 per share is typical to be held in this account, though not every broker requires that much, to guard against the "parabolic" move, so the margin requirements will be substantially higher than the potential gain if the PPS drops to zero. They do this since, in effect, they've extended you a loan when you borrowed the shares to sell into the market and they're going to make absolutely sure you can pay it back.