Above we see SPY going back to the start of 2015 (blue line). The red line is a cycle measure derived from the proportion of stocks trading above various moving averages. It acts as an overbought/oversold measure. Note the change in the distribution of the cycle measure from early 2016 forward. It was at that time that we saw a corrective period end and a bull market leg begin. The market still cycles (we are in a corrective phase currently), but the dimensions of those cycles are greatly different in an uptrend than in a flat/corrective market.