both of which are circled in the chart. These two events were rather violent reversals of the strong trend favoring growth that began in May 2007. These reversals were among the sharpest in the history of this spread, and both were substantial periods of downside risk for many quant traders, particularly those in equities. This is because the prevailing pattern of behavior, on which the quant bases forecasts of future behavior, becomes inverted at such times.