Do not set your price target on VXX, but use the spot VIX as your guide. Because of contract roll yield, and contango, the price of VXX will depreciate over time, regardless of market conditions. So you can not say that VXX was 32 when the S&P was at 1426, and expect that price ration to remain in tact. Instead, look at a spot VIX chart, and arrive at a target and set a stop, based on that. For example, I will be looking to sell my long position and get short if the spot VIX goes below 16. I am taking longside profits at VIX 20 and looking to get short if we get a one day spike to 25....where ever VXX is when VIX hits these points should be your targets, as there is no way to correlate values when taking into account the futures contracts that are rolled every month.
Well we have already done 20% off the low in VXX. A truly impressive move, no two ways about it. Getting that feeling like it wants to go up every day for a while now. Not sure if I think it will get back to 32 area where it began the year though.