I've been on this situation more than a few times.
There was a time that I executed and got out as a ten bagger. It was so stressful that I wake up at 2 am and thought I miss the opening of the bell. The kicker was it fluctuates from gaining $30K a day to loosing $30K a day. At times, I get myself intoxicated enough so I don't feel the stress so much.
Every minute it ticks, either I loose $5K or gain $5K. I have GTC (Good Till Cancel) orders at ungodly amount of price and broke it down to 10,000 shares so Level 2 will not show a big sell. When I see a big bid, I change the selling price just above the bid and execute. I did this for 3 days when the pps was on the way up. There's no such thing as executing all your shares at the peak.
Selling 1 million shares is not easy. It's stressful enough to get to 1200%. But selling is a lot more stressful.
There was also I time that my shares gained over 600% in 2 days because of an FDA Approval. I thought it was gonna go higher but only to tank on the 3rd day. Lost 50% of gains in two hours.
Bottom line. Stock investing is gambling. No matter how you look at it. Be prepared for a big loss. Be prepared for a big gain. Either way, it's stressful if you don't have the stomach for it.
Most of the time, I sell 50% of my shares and ride the remaining 50%. For sure, I locked in some gains. I found this technique effective and less stressful for me.