I think there is still more upside to come but what's disconcerting is the high volume on pullbacks, generally I've found that spells trouble brewing, especially after long runs (and not at bottom of trends [blowoff bottoms] where this sort behaviour also occurs frequently).
Volume through the first quarter has been lower on average compared to the last few years. And in general, there is always higher volume in indices on the big down days as compared to the big up days. I wouldn't put too much importance on volume levels as we enter the "classical" sell in May and go away period.
In this market, unless you’re extremely skilled, you shouldn’t be shorting shit. It’s long or flat. If you’re short, it better be part of a spread. Price rules momentum. Rty failed head and shoulders- which might mean a face ripper, nq with a textbook cup and handle about to form. Global markets hitting ath’s or 52wk highs. Why stand in front of speeding trains? These are low probability trading ideas to short in this market.