Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Accepted indicators for stock market valuation 
There are several camps for stock valuation, and much of it boils down to your investment style.  A growth investor will not consider something with a 50x P/E ratio to be overvalued, but a value investor certainly would. I would recommend looking up the Fama-French n-factor model (it was 3-factor, I believe they have released newer papers which introduce other factors), and reading The Intelligent Investor by Benjamin Graham.  Graham's methodology is practically canon for many investors, and the methodology focuses on value, while outlining quantitative factors for determining if a stock is under or over valued.