abbam...Here is a list of a few Market Makers that trade in the OTC and Pinks (copied from another site)
There are 2 categories of Market Makers let's talking about the first one.
Retail Market Makers:
These are the market makers from very popular brokerage firms. They handle a lot of the order flow for small retail investors.
NITE: NITE
SCHB: Schwab
TDCM: TD Water House
SBSH: Smith Barney
MLCO: Merrill Lynch
ETRD: ETRADE
GSCO: Goldman Sachs: New Kid on the Block, very active lately.
This is the list that you really have master because these are the MARKET MAKERS that handle promotions, insider transactions also S-8 and CD Transaction.
CD: means Convertible Debentures they are loans the come due and get sold into the market by the loaning company.
There are lot market makers in this category so I will break it down to who are the most important: These are some of the more active MARKET MARKET MAKERS on the street:
FANC: major S- 8 player: if there is an S- 8 on a Stock most likely he will be there on the ask until it dries up
HDSN: major CD Seller Handles a lot CD transactions.
VIEW: love when he’s on the bid
DOMS
MAXM: one of favorites: smart money more like a trader than market maker replaces GNLN for now.
VERT:
CLYP: heavy seller if you see him on the bid it's unusual
HILL:
FLCR:
SACM: love when he’s on the bid
JEFF:
VFIN:
AYME:
STCS:
ABLE: like when he’s on the bid
PBLC
VFIN
PERT
BKST
BNCH
ECN MARKET MAKERS
ARCA (formally GNET): very active used by traders market makers any one can use ARCA you have to know what your are doing. If you have access to ACRA trading system you can use the ecn.
TRAC: owned by my track if you trade with my track you can use this to place your trade as a liquidity outlet same 4 data
DATA: owned by my track same concept as GNET & TRAC
There are probably a few market makers that I left out or there will a few new market makers that show but for the most part these are the major players. Good luck hopes this helps.