Today's chart comes from Jason Goepfert at SentimentTrader.com. Last month, Jason told FS Insider that sentiment readings were reaching extremes, even surpassing 2000 tech bubble-levels of euphoria, which was a "very troubling sign" for the stock market (see Rydex Trader Bullishness Surpasses 2000 Tech Bubble).

This most recent data looks at the total number of Hindenburg omens for the S&P 500, Nasdaq, Dow Jones Industrial Average, and the Russell 2000. In sum, "we're seeing a market that is split between winners and losers to a degree rarely seen in history," Jason wrote in yesterday's Sentiment Report.

(Click on image to enlarge)

Source: SentimenTrader.com

You may be asking yourself, what is a Hindenburg omen? Here's what Investopedia has to say:

DEFINITION of 'Hindenburg Omen'
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).

Additionally, they write:

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.