Do you think if someone will know they aren't rich enough now?
Because the crypto market is unpredictable, you will only know that the price is corrected after how many days seeing the price compared to the previous one, if the price drops something like 15% from the previous, that is being corrected price but you don't know exactly when it will occur.

There are some traders using technical and fundamental analysis for this, but against this is not a perfect tool to predict the market, it is just speculation either it is accurate or far from the result. Juts invest and hold for a long term and there is no need to wait for a massive correction, we don't know how can be folded bitcoin in the future or how many folds when it has a correction, so invest at your own risk.