I think this is easier said than done.

You most likely need to wait until it's close to 3 X the value you bought it because you'll need to pay short-term taxes after you sell it.

And once that happens, why sell half of it, vs all of it? 3 times the current value is a LOT of money and that usually takes at least 8-10 years in the equity market. Now that it happens, you're cashing out just to recoup your costs? Cash out everything, or cash out nothing and let it all ride until it's an even larger amount.