market maker

noun

a dealer in securities on the London Stock Exchange who buys and sells as a principal and since 1986 can also deal with the public as a broker

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012