A law enforcement action alleged that on several trading days over the course of two months, defendants engaged in a series of copper, gold, crude oil, and natural gas futures transactions on an electronic trading platform. One defendant repeatedly bought future contracts at low prices from the other, and then immediately sold them back at higher prices. As a result, one defendant effectively pocketed the same amount as the other lost even though there were no changes in the open positions held by either defendant. What is a name for this typology?

The bid-ask spread is the difference between the buying price (bid) and the selling price (ask) of a security. It represents transaction costs and market liquidity rather than a trading strategy. It does not apply to the scenario described, where the focus is on the manipulative practice of trading between the same parties.

Reverse flip is not a widely recognized term in trading terminology. It may suggest a reversal of a typical trade but does not accurately describe the actions taken by the defendants. Their transactions involved simultaneous buying and selling, which is characteristic of wash trading rather than a reverse flip.

A short position involves selling a security that the seller does not own, anticipating a price decline to buy it back later at a lower price. This concept is unrelated to the scenario, as both defendants were engaged in futures transactions without the intention of profiting from price declines. Their actions were instead about creating volume without real market risk.