A more thorough explanation:

Definition: Coemption is the act of buying all of a particular item or commodity.

Examples:

• A company may engage in coemption by purchasing all of the available stock of a certain product from a supplier.
• A collector may practice coemption by buying up all of the rare stamps in a particular series.

These examples illustrate how coemption involves buying up all of a particular item or commodity, leaving none for others to purchase.