Many people regret that they did not buy BTC while they first knew about it. For some, they did not sell BTC while they could.

For me, I got MWC & HEX for free from airdrop to BTC HODLers, but dumped them before they peak. I could easily make 10x of my existing BTC, if I held them strong.
What is your Biggest Crypto Regret? My most regretful thing is not participating in crypto earlier. back in 2016 I had heard about bitcoin and its functionality, but I hesitated because I was afraid of being cheated. after 2 years, the price of bitcoin skyrocketed to nearly $ 20k and the bounty projects were very successful, there are many bounty hunters who have earned more than $ 100k. I wish I had the knowledge of technology soon, but now I have become a millionaire.