For example, $VIX was sub-20 from 2004-07. 2004 was a dog year for $SPX, the other years were very good. Note, however, that $VIX would occasionally 'burp' 50-80% higher during that period, and $SPX would decline more 4-7% for 1-4 months. The notion that this was a period of consistent low volatility is wrong