"still a triple bagger"
Zeev, I expect much better from you. Cost basis is IRRELEVANT to making appropriate investment (and trading) decisions - except insofar as tax events are concerned.
A definite tip of the cap and kudos to you on this one and many of your core holdings -- which I am sure everyone appreciates you sharing. My personal favorite has been POOL, an incredible secular roll-up story in a tremendously fractured market with a high-quality, steady management team.
Having said that, though, tax considerations aside, the decision about whether to hold is entirely about judgment/assessment of future risk/reward, not about how large a gain one has. It is just as large a "sin" to lose "paper gains" as it is to lose cash from the bank. Those gains are yours, today.
It was the failure to think properly about this that caused such devastating losses for so many during the 2000-2002 market decline. Each day, there is a decision made to take the full amount of capital and apply it toward the further future prospects.