If I purchase an option, can I sell it before the expiration date, or do I have to exercise it? Or is it too difficult? I'm asking because most are OTC traded.
If you're talking exchange-traded options, then certainly you can sell them. If it's an OTC option, you may be able to sell back to the original seller. Alternately, you can sell a second option with the same strike and expiry terms.
What are the differences in liquidity between ETO ad OTC? I traded stock options in the past, and sometimes they're hard to get rid of. Where can I get quotes, any websites?