Currently XMR is in its very early stages and its rare for such a project to get so much attention so quickly. Given this fact the currency is volatile and the swings can be quick a deep, that being said there is a lot of serious money invested in XMR so you know your not going to buy a shitcoin that goes down to 1% of your investment.

If you are worried about getting in at the best time then I would advocate cost averaging your way in at least over a few days if not weeks.