Judging from investors' reactions, the only thing worse that than the low volatility environment is when volatility spikes higher, as it did yesterday. Higher volatility is associated with weakening equity markets, falling interest rates, pressure on emerging markets, a strengthening yen and, sometimes, as was the case yesterday, heavier gold prices.
Read more here: http://www.marctomarket.com/2017/05/markets-trying-to-stabilize-ahead-of.html