Hindenburg Omen

What Does Hindenburg Omen Mean?
A technical indicator named after the famous crash of the German airship of the late 1930s. The Hindenburg omen was developed to predict the potential for a financial market crash. It is created by monitoring the number of securities that form new 52-week highs relative to the number of securities that form new 52-week lows - the number of securities must be abnormally large. This criteria is deemed to be met when both numbers are greater than 2.2% of the total number of issues that trade on the NYSE (for that specific day).

Investopedia explains Hindenburg Omen
Traders use an abnormally high number of 52-week highs/lows because it suggests that market participants are starting to become unsure of the market's future direction and therefore could be due for a major correction. Proponents of this indicator argue that it has been very accurate in predicting sharp sell-offs in the past and that there are few indicators that can predict a market crash as accurately.