Bidding Ring

A group of people working together to keep the prices artificially low (or artificially high, depending on the scenario) by agreeing not to outbid each other. It's a form of collusion that's generally considered fraud.

Say a construction contract is up for bid. You and your buddy are the main competition for the project. But instead of putting in truly competitive bids, you guys get together and decide that you're going to put in the same amount. This way, whichever one of you gets the final bid, that person is going to make more than if the bidding was fair.

In this example, you and your friend are the bidding ring, and what you've just conspired to do is called bid rigging (See: Bid Rigging). We expect you to go to your room and think about what you've hypothetically done.