Found on net
Sell gamma.
Generally, this means you are selling short dated straddles and delta hedging. The reason is that implied vols generally trade at a premium to realized vols. So generally this strategy will make money and is a positive carry trade. Unfortunately it is also the definition of 'picking up nickels in front of a steamroller.' When the world is in a "normal" state, you are making money, but when stuff hits the fan you are exposed to huge drawdowns.