I want to know why options don't trade in penny increments? It seems that options that trade in penny increments would be a joy to trade. Tons of traders would start trading options so now why would the options exchanges mandate .05 spreads, it seems against their self interest. Now I know IB has a penny increment program, but I think its in internal thing - ie if I post a bid at .37 then only other IB users can see that bid - its not posted on all the exchanges (am I right on this?).