The SI Formula

Current Dividend Yield > Average Dividend Yield : Stock is undervalued

Current Dividend Yield < Average Dividend Yield : Stock is overvalued

The Warren Buffett Value Formula

The Most Value for the Least Price:  Net Earnings + Dividends / Price-To-Book
If Value/Price is greater than 10 => Buy, will likely rise in price
If Value/Price  is less than 2 => Short, will likely fall in price

Aswath Damodaran’s website   http://pages.stern.nyu.edu/~adamodar/