That's the strategy I did. I will not empty my wallet just because the price of bitcoin is in a high position. I will hold a few and expect a better price the next day. If it turns out my prediction is wrong, I will not lose because the coin can still be held.
It's not more people thinking it about. Even if the prediction gone wrong, you still can earn with another altcoin that you hold meanwhile bitcoin price will be recovery slowly. it's just the time that you need to hold bitcoin is increases, but because it is bitcoin, there should be no doubt when holding it.