I own 300 shares of NCLH, I sold a call last Monday with strike price of $16 when the stock was at $15.8 for a premium of $115 (for the 3 calls). The Call expires tomorrow and I don't know what I have to do. If I don't do something the shares will sell correct? What is the best way to keep the shares (NCLH is at $16.8 right now); or what is the best thing to do in this situation? Thank you!
The best thing to do depends on what the stock actually does going forward.
If NCLH is above $16 at tomorrow's close, you will be assigned and your shares will be sold at $16.
If you buy back your short calls, you will realize a loss on them but since NCLH is higher, you have a net gain due to the appreciation of the stock. I am not a fan of realizing option losses and then carrying paper gains because the market has a perverse way of making you pay for that.
The other alternative is to roll you calls up and out (higher strike, later expiration) for at least break even or better. The later the expiration, the higher the strike price you could roll to (7/17 $17.50 call or 7/24 $18.50 call). Note that these are break even rolls. You could roll to any strike/week of your choosing.
There are lots of web sites that explain this. Here's one that I randomly grabbed.