The only times the monthly (14) of this chart went over 70, a crash eventually followed. However notice the period from 1994 to 2000 where hovered around 70 for a long time before there was a crash.
Take this chart with a grain of salt. The current fundamentals are much different then in the previous crises and a real crash is still unlikely. However, embracing for a good a legitimate correction in the stock market is reasonable.