• Date: March 19, 2014

On March 19, Janet Yellen learned the hard way how a minor slip of the tongue by the chairman of the Federal Reserve can instantly spook the market.

Asked by a reporter to define what the Fed meant about waiting a "considerable time" before raising interest rates, Yellen said that "probably means something on the order of around six months or that type of thing." The Dow fell as much as 180 points after her remark.

But a rate hike as early as September was not what Wall Street had been banking on. So the markets threw a temper tantrum, fearing the Fed would boost rates before the economy is ready for it. In fact, it took the S&P 500 nine trading sessions before recovering from the Yellen-fueled pullback.

NEXT: Momentum meltdown