This article is not intended to be taken as professional financial advice; this is just an opinion from a random person on the internet.
The age old question: Should I sell or hold? My personal answer is that a balance of both is important, but lean more toward holding. If you sell, you cut your losses (as well as your gains). If you hold, your coins can gain considerable value over time at an opportunity cost of not having those funds to invest in other coins at the moment.
When a coin skyrockets in price, some people sell ~20-30% of it to hedge their bets: this way they can still make quick money on it before a possible correction while also having enough to profit from it in the long-term.
Some people profit from it. Most don’t. Worst of all, it’s not worth the time. Why spend hours a day glued to a coin exchange website when you can make the same (if not higher) margin of profit by just buying good cryptocurrencies and holding them?
Some people thought they were making decent money by trading Cardano between 24 and 28 cents. But the problem is that it shot up all of a sudden to 70+ cents (while they were asleep) and now those same daytraders will need to spend what they made on daytrading in order to buy in. Worst of all, daytrading eventually gets people into a trap where they impulsively buy a coin on a dip that they think will surge, but instead plummets.
Why Holders Win
I had made some dumb mistakes in December. I’m human. I bought Stellar Lumens at 22 cents, held onto it for a while, but sold at 26 cents once I saw that it wasn’t making any real progress in 2 weeks compared to other coins. Now Stellar Lumens costs 52 cents and I’m kicking myself. I bought Ripple at $1.10, sold all of it at $1.40. Then, I had to buy back in at $2.20. Whatever profits I make in the future (even if it goes up to $5/$10/$15), I’ll now be making half as much ROI as if I had just bought it all at $1.
Assuming that the currency is from a team that is qualified and competent, and you see long-term potential for the coin, it’s way less stress and time to just sit on a coin for months and watch it grow overall rather than sweating about every single little correction and making bad decisions out of haste.