My understanding is that they don't usually end up with stocks, but their handling of this specific situation created what amounted to a short position. Essent

My understanding is that they don't usually end up with stocks, but their handling of this specific situation created what amounted to a short position. Essentially, the bug (whatever you want to call it is irrelevant from the financial angle) meant a bunch of people wanted to sell facebook stock and were unable to do it. They said that they were willing to sell at the current going rate, which was $42. NASDAQ was unable to process the orders, so they weren't able to process the sales. The resolution they settled on was essentially becoming the other party to the transaction: they would provide the FB shares to the (possibly disgruntled) customers at the same price - as if nothing had gone wrong. But, as this is happening, NASDAQ doesn't actually have FB stock - they have to buy it on the market later. Like a normal short, they benefit if the price goes down since they have to spend less to get back the shares. For example, if FB went down $2, NASDAQ only has to pay $40 for the share, and they make a $2 profit. This is all a long-winded way of saying they didn't have a short in the traditional sense, and in normal cases this doesn't happen, but it happened as a result of this screwup.