For options positions that are short gamma, there is a risk that price movements in the underlying will cause compounding losses. For instance, if such a position begins delta-neutral and the stock rises, it will produce increasingly short deltas for the position, so that as the underlying rises, the options will lose more and more money. The risk, however, is that if the deltas are bought at these ever higher prices, the underlying asset can reverse direction and fall, creating long deltas on the way down, compounding those earlier losses.