What follows about P/E probably will not change your mind about investing. Unless you have read what I relate about my experiences, investigations and research over the years, during which I have looked at the pros and cons of over 1,600 investment strategies.
Price/earnings is not a viable strategy for a number of reasons I’ve given in the past. Primarily, it has too much fleeting, irrational psychology involved in its use. Furthermore, price/earnings numbers are too relative to other conditions and price movements.
You cannot reasonably buy securities by historical price earnings comparisons, though Wall Street professionals get tangled in this strategy all the time. The cycles involved are too economically, politically and internationally influenced and thus imprecise. (See the Earl J. Weinreb NewsHole® comments and @BusinesNewshole at Twitter.)