Today? No. Yesterday(22/12/2017-the date when the market crashed), yes. But is it too late to buy XMR? Depends on what you're planning to do with it. If you're buying it for a longer term, well good news for you, you can still buy it, store it in your hardware wallet. But if you're looking for a short term trade, then you can be faced with a possible sequence of circumstances which is too risky at the moment. Since it's XMR, I'd seriously like to suggest you to hold it for a long term, it'd be worth the time and the money. Cause you know how popular XMR is and how lit it's features are.