For noobs, HODLing is a term used for "holding" your assets (here: Bitcoins) for a very long time. But, isn't it true that those who bought it at $500 once should have sold it at $20k peak, and if not, why didn't they sell at $15k? BTC didn't crash all at once and they had the opportunity to sell and wait for another opportunity. A $15k per BTC against a $500 BTC - means a 30x return itself. And BTC crashed to $3k, if not $3k, then these hodlers would have bought back at $6k which is even less than half of $15k as they would also have added a lot more liquidity to the markets with too much money on the table. Isn't it true that too long a hodl can stop you from taking great opportunities while sitting dumb and waiting for a specific target?
This is the reason why people should know how to control their emotion and must know where should they take profit. This is like FOMO and greed at the same time. You think that if you sell at $15k, it could go higher so you hold. When BTC peaked at $20k many didn't sell because they thought that it would go higher and that's because of greed. When it dipped they still hold because they said it would recover but its price continued to crash and bottomed at $6k. Hold is good but you should know your exit.