Thanks Chris and mdl, clear answers!
Quote from ChrisRT:
Market Makers are typically firms but with the ability to use ECNs, we can in some anecdotal way become market makers ourselves as we add and take away liquidity also...we just aren't "required" to keep a fair two sided market. So if stocks are tanking, we don't have to support them. Market Makers have obligations to step in front of faster selling in order to not let a major panic occur for too long.
Quote from facultus:
If you were to buy a MM ID what would you do with it?
What is the capital requirement to make markets?
Besides making markets, what other advantages are there for having a MM ID?
How much does it cost now to become a market maker?
Thanks!
Quote from trade4succes:
Maybe that's another good question for the (ex-) mm's. Do you have leeway to advertise in order to push a proprietary (or non-proprietary) position your way?

)))