The SPX held a key area of support at 6,400, but Kevin Green adds that weakness chipped away at the index throughout the day. Holding the 20-day SMA will prove critical, as a multi-day break below the metric can open a trap door to steep selling action. Kevin then analyzes volume in the SPX, also showing downside action over the past few trading sessions. On the 10-year yield, he's expecting a "pivotal" breakout or breakdown that can shake up equity volatility.