What not to do with stock prices

Last week, I discussed how an illusory idea of the 'price' of a mutual fund created problems for investors. Investors think of the NAV of a fund as its price, which leads to flawed concepts in the way they choose funds. The worst aspect is to compare two funds on the basis of NAV and think that in some sense, funds with the same NAV must be similar. Are equity investors immune to this problem? After all, while mutual funds don't actually have anything called price, stocks do. The price of a stock legitimately plays a central role in investing, so one would expect equity investors not to have any misconceptions about price. Unfortunately, this is not true. Stock investors are prone to the exact same flawed mental model