Lately, I've noticed that Stock Screener is slow to react to earnings changes, and occasionally misses a stock that should be in the Low P/E Bin. I've tried to compensate by manually getting rid of any stock I've found whose P/E has expanded because of earnings drop, but my doing so only covers one part of a proper adjustment. The other part, finding stocks that have entered the Bin because their earnings have gone up, I cannot do. There's too many stocks in the entire Stock Screener universe; if that filter doesn't work properly, I have to search manually. Finding new Bin stocks in the entire stock universe requires too comprehensive a manual search for me to do.
I've decided that working one end of the earning-changes line, but not the other, will introduce a further distorting volatility in the number of stocks in the Bin. A long time ago, I was taught that it's best to be accurate but it's second best to be consistently wrong; the latter is easy to fix and doesn't bollix things up more. In this situation, I cannot be completely accurate; so, I'm going to go back to using Stock Screener without anticipating it anymore.
Buffett's annual letter
4 hours ago