Except knowing this is not the hard part - even professional investors sell too early on the upside and hold on to the losers too long. What does "already appreciated" mean? Is it Amazon today? or stock you bought for $60 and sold for $300? Is Walmart "cheap" today because they're well positioned for distribution from digital sales, or expensive because their bricks&mortar stores are dinosaurs?

So, yeah, we can mine his answers for subtle nuance, but it seems we quickly return to the crux, which is "but how?"

A long time ago, I read about a guy who made a lot of money on the market. Someone asked him how. He said, "I always sold too soon."

You aren't going to know if it's too soon to sell Amazon. But if you wait until it's not too soon, it will be too late.

But of course, there's "too soon" - say, when you've made 70% of the possible gains. And there's "really too soon" - when you've made 5% of the gains. How do you know which is which? I don't know.

Sure, I'm not arguing with that. I was just saying that the OP's criticism is a bit misguided. Yours is more reasonable.

Eh, the answer to "but how" needs to be understood before you can "buy low, sell high." I don't think my criticism was misguided at all.

> assets that have already appreciated

There in lies the rub.