corner the market
Buy all or most of a commodity or stock so that its price goes up. For example, In a famous maneuver the Hunt brothers cornered the market in silver. This idiom uses corner in the sense of “drive would-be buyers into a corner.” [Early 1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.