market makers BUY and sell options based on their true theoretical prices. they dont always buy back the options they sold due to illiquidity but rather hedge their positions by buying different strikes to spread their volatility risk.
I trade various products these days. I use cityindex spreadbetting platform and also have an account with Fimat Singapore. I was planning on setting up an office to trade index options in the alabang area but its' too costly for one person.
What about yourself?