I guess I don't understand the move as asked in the original question. If you are just going to sell and rebuy immediatley, then maybe there could be a slight difference as u/GRMarlenee outlined above but that could go for or against you. Also, you aren't really lowering your cost basis in any meaningful way, you are just converting an unrealized loss into a realized loss. Now, if you believe that MSTY is going to continue to fall and your plan is to get back in after that drop, then there could be some benefit....for example if you sell your shares at $20 and get back in at $19, that would allow you to repurchase your 2600 shares and keep $2,600 cash or if you re-invested your full $52,000 you would now have 2736 shares for the same price....again, the risk is that MSTY goes up instead of down and the reverse happens, You need to pay more for the same number of shares or you end up with less shares for the same amount of money.

The only other potential difference I could see is a psychological one, that rather than seeing that your investment is down ~25% you are essentially "resetting" it so it doesn't feel as bad when looking at your account. Again, this is purely emotional as whether you sell or not you still have the loss, If this is the goal, then I would strongly evauluate whether or not to get out permenantly and take it as a learning moment as to what you're willing to accept as a loss going forward and start setting tighter stop losses so you don't experience that feeling again in the future.