The NYSE 52 Week Highs & Lows is a plot of number of NYSE stocks that have made a new 52 week high or low on the last trading day of each week, usually Friday. The chart is updated weekly, usually on Saturday.
Strong markets or confirmation of market breakouts are usually signaled when the number of highs exceeds 100 and the number of new lows is less than 25.
Market bottoms are usually indicated with new high readings below 50, and new low readings in excess of 150.
Market rotation is usually signaled when both highs and lows exceed 80 at the same time.