With the 12% rise in the market since the beginning of the year one of the notable side effects has been a drop in volatility (another notable is a drop in correlation). The 50-day average high/low spread of the S&P 500 has fallen to 0.93% down from its recent high of 3.01% in October (the average daily high/low spread since 1990 is 1.36%). There have been twelve other similar instances where this measure has crossed below 1%.
Historically the market has reacted positively to a drop in volatility. Following a drop below 1% high/low spread the S&P 500 is, on average, up 4.36% over the next six months and was positive 75% of the time.