My friend asked me the same in 2014. and I answered: no, it's never too late. Always buy again. he did not do it. I bought ;-)
I agree with
Daydream for cryptocurrency investment is never too late. I give you one tip that no one mention but it comes with a price (maybe high...) Some Tokens/Coins are expensive and like Litecoin just recently raised in value you can still buy but for better profit (much higher) this is the way:
buying more cheaper coin/token will always work out better than have 2, 5 or 10 coins more expensive. When I mean more is 500, 1000, 2500 ideally 5.000 This comes with a price, risk is greater than buy more solid and more expensive ones, but reward beats anything for sure because of multiplier. x500, x1000, x2500 and x5000