No idea. Are you an investor or a speculator? How to tell the difference:
1. Investor: You believe in the long term future of the business?: Buy in when you can at any price. Price fluctuations dont matter. Entry price is irrelevant.
2. Speculator: Minor fluctuations make you sweaty. You lose sleep when a stock goes down.
Basically are you trying to time the market (speculator)? There are millions of books on this topic.