Here's a wild firstworldproblem. I'm torn. On one hand, I have ALWAYS wanted a Ferrari. Here I am able to buy one, something I never thought would happen. I could sell now, get my ferrari and be happy. On the other hand, I could hodl, it could either go up or down. If it goes down, I feel satisfied with my choice. If it goes up, I will feel some regret but fuck it, I have a god damn ferrari. I have a house and no debt, perhaps I'm just being greedy at this point and should get the one thing I've wanted and be happy with it. Fucking wild decision I never thought I'd even have to make.
If you have to think that much about the situation, then a ferrari is out of your budget.
What if we have a doubling from here, then perhaps at that time, a ferrari would be in your budget because you could use half the previous number of coins to buy the same car.
You have permission to buy a Ferrari when it is less than 10% of your stack. And not before.
Hahahahaha... those are much more specific (and ultimately better) guidelines than the ones that I attempted to give.... so yeah, instead of just randomly saying: "I have enough for a ferrari", you calculate some kind of reasonable formula, and sure, I am nearly as conservative as you, which would be something like 10%, but for those who are not as conservative, they might tip at 50% but lower is a bit better, especially when buying a most likely depreciating objection (or a consumption good).