Market internals show that since Feb 16th. the market has been advancing on fumes:
It is entirely possible, that in a very strong uptrend, the market can continue grinding higher, while market breadth gets through a declining cycle, but those are rare events. The most likely scenario is that the indices will enter a consolidation phase since bearish momentum rarely follows immediately after a prolonged period of bullish momentum.
Tightening stops is the prudent course of action.