A sub-15 VIX (Friday close 14.7) is rare, says Goldman Sachs, and it doesn't stay below that level for long (true post-2007, pre-crisis not so much). It's not just the U.S., but implied volatilities have dropped across every global index followed by the Goldman team. Another sign: The put/call ratio has declined to its lowest level in more than 3 years, as players pull off hedges.