Warren Buffett’s Favorite Indicator Just Flashed 'Warning'

 | Dec 27, 2017 12:15PM ET

It is clear stocks are in a massive bubble based on their Price to Sale (P/S valuation).

What about the economy?

Warren Buffett once famously stated that his favorite means of valuing stock was the stock market capitalization to GDP ratio.

Below is a chart for this metric. As you can see, the stock market today is as overvalued relative to the economy as it was at the peak of the 1999 Tech Mania.