Exercising an option is buying the amount of contracted shares at the agreed strike price. Selling to close the option is most likely selling it back the party that sold it to you (Hopefully for a profit). Its really hard to predict what the options will sell for IF AMRN were to go to 26, but a jump of at least 1000% (yes 1000%) can be expected. For example, I was very bullish on SRPT early in Oct., but didnt want to risk alot of money. At the time I bought the calls SRPT was at around $12. The stock later had a run all the way up to $45 and the calls became hyperinflated by about 20,000%. Options are very powerful when you're on the right side, but one can lose all of the investment on the wrong side.
On a side note, I bought out of the money calls as well hoping for a short squeeze. I hope alot of people are dumb enough to go short for hopes of the options market to become superinflated.
In 2008, the day the stock market crashed, I watched Index put options on the Nasdaq go up 10,000% in about 40 seconds. Thats where the transfer of wealth happened in America.