Right now the S&P 500 (and each of the major US indices) is trading close to break-even point for the year, and near its 200-day moving average. For traders, these sorts of points present psychological barriers. The markets have rallied about 20-25% or so since the March lows. That kind of momentum is hard to keep up. If good news keeps coming in, or if some of the traders shorting into this bear-market rally get squeezed, we could see the markets move even higher. I would be surprised if this happened this soon though, as much as I would like to see it. If this board is any indication, some people were hunting for bargains, in March and April. Now I sense that there is some ambivalence, as in the current valuations aren't presenting the bargains investors want.
Maybe many companies had low-balled their Q1 earnings forecasts, leading to some positive surprises. By now, I would expect those positive surprises to be priced in to the market by now, with investors now looking ahead to Q2 earnings. Barring some unforeseen surprise events, I don't think we're going to break through this resistance until Q2 earnings come out. After all, stock price gains can't outpace earnings growth in the long run.
Of course talk is cheap, and I don't have anything to lose by making a a prediction.