The SKEW index was created by CBOE in 2011 to help deal with risk of large down moves in SPX. It makes only one reading per day, and yesterday’s reding of 153.66 was the highest since they started publishing readings. (see more inf o on SKEW here: http://www.cboe.com/micro/skew/introduction.aspx)

Typically, reading above 135 are bearish, and readings below 120 are bullish.