It’s simply too late to short. With SP500 down 11%, QQQ -13%, IWM -15%, since their 12/30/2015 high, it is simply too late. If you believe that this will be 2008 all over again, chances are high that you might get an opportunity to short at better prices. As you can see in the chart below, 2008 started with a 14% decline that was followed by a 10% dead cat bounce that led to some sideways action.
The largest rallies have happened in bear/corrective markets that are below the 200-day moving average as you can see below: