Cyber attacks are on the rise worldwide lately, more so now more than ever , and we know that the more technology increases, the better cyber attackers become as well. What happens if a cryptocurrency gets hacked? Everyones fortunes GONE!?
a cryptocurrency in general meaning the altcoins can get hacked because they usually don't have any decent developers and they are full of exploitable bugs, even those altcoins that are staying on top in the 2, 3, 4... ranks and they have already been exploits or hacks if you want to call it.
but if you mean something huge as bitcoin as a cryptocurrency then no it is highly unlikely because for 8+ years they have been trying to hack it and failed. for 8+ years good developers have been working on it and thousands of developers have gone through the code and fixed any possible bugs in early days and they still peer review bitcoin.