I think there no safe when it comes to cryptocurrencies. That said, I myself have some of my savings invested in cryptos, but definitely, not all, I am not that mad yet .
As an investor, I would never ever invest all my wealth in just one single investment. I diversify my wealth in different investments. Always diversify no matter how good the investment looks! Btw I invested a % of my wealth into crypto because I am very bullish on the long term.