If you require an example of the high risk of high valuation, the past few weeks should be all the proof you need.
The huge drops in shares of Netflix, Vertex Pharmaceuticals, Green Mountain Coffee Roasters highlight the high-flyer danger.
Arguably, those names are a little different than most. They are all small or mid caps with high valuations that generated intense debate among traders both long and short the shares. Call them the kings of volatility.
They also proof that valuation still matters.
With that in mind, we thought it better to dig a little deeper into valuations of larger, more mainstream stocks, and our crack CNBC data team dug into the S&P 500 looking for the 10 stocks with the highest PEG ratios.
PEG is the short name for the price to earnings to growth ratio. New York University’s Stern School of Business defines it as the ratio of market price to expected growth in earnings per share. It was known as a favored starting point in valuation searches by famed investor Peter Lynch.
Like any of the screens on CNBC's "Street Signs," this should also just be considered a simple starting point for investors and more work should be done to dig into the "why" on these ratios.
That said, below is our list of the 10 stocks in the S&P 500 with the highest PEG ratios.
All data comes from Thomson Reuters.