RESISTANCE

When referring to the price of an issue over time, resistance refers to a price ceiling that the issue does not exceed. There are several possible reasons that the price can’t rise above this resistance level. One of the more common reasons is that, at that resistance price, the number of shares that sellers want to sell exceeds the number of shares that buyers want to buy. Hence, the supply exceeds the demand, so the price will fall to an equilibrium point where trades can take place. When the price won’t fall through a price, that is support.

Complete defintion with example chart (in new window).