Lowest volume since Feb 19 & flat OBV -> market reversal?

The S&P 500 (SPY) has hit its lowest trading volume since Feb 19th (right before the crash). In addition, the rally this week has had a relatively flat on-balance volume. S&P has also failed to retest April 29th high. Nasdaq has stalled at 9200. All these signs point to a high likely hood of a reversal in the markets.