The Option Chain of a stock is given below. The stock price now is $22.50.
If I sell a $21 put, I'll receive a premium of 15 cents and I will be obligated to buy the stock at $21 if it is below $21 at expiration. If the stock is above $21 at expiration, I will keep $15.
If I sell a $24 call, I'll receive a premium of 20 cents and I will be obligated to sell the stock at $24 if it is above $24 at expiration. If the stock is beow $24 at expiration, I will keep $20.
How do I interpret this and how does the collection of the premium work?