a.) Until yesterday, the market was in a strong uptrend. However,
b.) Notice that support became resistance during yesterday's trading.
During the rally, there were four gaps higher, at points a, b, c, and d. That tells us a supply/demand imbalance existed overnight. In addition, notice that on two days the overnight move -- along with a quick, post-opening move higher -- were all that happened during the trading day.
a.) Since February, prices have been in a sharp rally. The degree of the rally is one that can't be maintained -- it's simply too sharp a move higher to have any staying power.
b.) Prices are again at important points of resistance.