Looking at what's going on in the crypto market right now, investing in bitcoin and holding it really seems like the safest option.
It can be said that there is already a rule that when bitcoin rises, altcoins rise even faster, but when bitcoin falls, all altcoins fall, much more than bitcoin, and many altcoins never recover, unlike bitcoin, which has been around for 13 years.
I still regret my mistake when I invested part of my bitcoin earnings in 2017 in some promising altcoins, which failed in 2018 and never recovered.
During that time bitcoins have fully recovered and I have no doubt that this scenario will repeat itself for bitcoin.