Hold or sell GRAVITY

I bought 4 shares of GRAVITY in July 2020 during the pandemic, each share was like $60.( I was new to stocks so I wasn't going to invest alot) Gravity went up, with its all time high being $239 per share in January 2021. I didnt sell, I held because I was sure the stock would continue to go up because it's an online and gaming software company. Since then, the stock plummeted all the way down to $77. Missed a huge boat and I regret it. Do you think gravity will ever increase like that again ? Or should I sell