On May 9, 2013 we had a rapid sell off on 1 min time frame. I don't think it is something to worry about, because price action had formed a head and shoulders pattern, then we had huge spike (parabola move). Parabolas moves are not sustainable for very long of periods. So I think that head and shoulders pattern with the parabola pattern made a deadly combination to cause this fast downward move. Also the indicators are showing a divergence. This is my explanation of the rapid downward move in terms of technical analysis. Have nice day fellow traders.