I think it is really risky to invest today because most of the coins are bullish specially the top coin, but there are still some altcoins that is also a promising coin that still low at price, you can search those altcoins and invest on it. Risk is depend on how we choose or decide on what coin we are going to invest if you pick the right coin then good for you but if you pick the wrong coin then don't sell just hold you will only loss if you sell at loss.
If you are a long-term investor in the cryptocurrency market, you can buy anytime at this time. I still think cryptocurrency is a stub. If we compare bitcoin price now with 10 years ago bitcoin has increased a lot. But we continue to miss opportunities from now to 10 years from now, maybe we will continue to regret it. Opportunity will not come twice.