Market Makers can place bid/ask for retail or institutional clients, and some even use computer programs to palce their own trades.Both groups can play whatever games they want with the bid and ask, so rather curious why market makers always blamed when any retail investor can do the same thing, except market makers can short the stock temporarily until they settle accounts- and on otc stocks this usually means the same day, or if not within three days. urban legends about shorting penny otc stocks are just that , legends.
if retail investor wishes to tease the bid up, he can do so, then hit the bid when others jump in. investors typically love to buy high and sell low,so for astute trade understanding trading patterns and market maker reactions can be profitable.
market makers can trade on their own account but generally try to not hold inventory of stocks overnight for their own account-just not the business they are in.
