market-maker
noun[C]
STOCK MARKET(alsomarket maker)ukus(written abbreviationMM)apersonorcompanythatcontinuouslybuysandsellssharesinparticularcompaniesforparticularprices:
Theproposalrequiresacompanytradingmore than 1% of a stock'svolumeto belistedas amarketmakerfor thatstock.