Urban Carmel posted on TWTR the following observation from Sam Stovall:

So far, 2017 has seen 17 new all-time closing highs for the S&P 500 and just 10 days where the index moved more than 1 percent in either direction. That kind of higher highs with low volatility always – yes, always – has been positive for the market. The previous 17 times that has happened, the market has averaged a 19.4 percent gain, with advances happening 100 percent of the time.

my question would be: a 19.4% gain over what timeframe? the next 12 months? what were the comparison circumstances? how many new all-time highs and how many days of >1% gain/loss both over how long a time period

still an interesting point, nonetheless