The individual investor should act consistently as an investor and not as a speculator.
Graham cuts to something often overlooked: the difference isn't really about time horizon or risk appetite, but about *how you think*. A speculator imagines tomorrow's price; an investor imagines tomorrow's earnings and what a business is actually worth. What makes this distinction bite is that consistency matters more than being right once—the speculator who guesses correctly on Tesla might then sink his winnings into meme stocks, while the disciplined investor might boring-ly compound wealth through decades of methodical decisions. Watch someone check their portfolio daily versus quarterly, and you'll see who's thinking like a speculator trapped in an investor's clothing.