I really should give a better answer than the one I did above, so here goes.

There are a bunch of reasons a stock can start trading above resistance or below support. Earnings could be better than expected, industry or sector growth, favorable government policy, or, inversely, unfavorable government policy, industry or sector decline, earnings worse than expected. If a move is based on some type of fundamentals, than it is likely to be stronger because the value of the company, and therefore its stock, has increased or decreased.