The short term bull and bear cases are quite simple and both have merit. The bears will say the S&P 500 has shot up a very quick 70+ points. Even in the context of an uptrend we could see a pullback of a couple of percent, never mind if this is just a dead cat bounce.
The bulls will counter that despite this huge rally bearish sentiment is still extreme and most are still fighting this rally. In past years strong uptrends have kicked off with tremendous rallies. Most prominent is the rally that started off 666 in the S&P 500 and last Summers rally that started in late August. In both instances the rally was as sharp as this one and the market never looked back.
I see both sides of this argument which is why I am largely out of my shorter term longs but holding on to my core positions.