Perps allow traders to speculate on the future price of an asset with a typically leveraged position, and the contracts don’t come with a built-in expiration.

But CME, which operates the leading global venues for derivatives trading, has insisted the contracts are not futures, because they have no end date. They’re really swaps, the company’s argument would have it, which would come with an entirely different regulatory approach. Spokespeople for CME didn’t immediately respond to a request for comment on the CFTC’s latest filing.

The CFTC first asked a federal judge to dismiss CME’s case last month, and this latest filing details its argument against the company’s legal standing.

“CME must plausibly allege an actual or imminent increase in competition,” the CFTC argued. “CME has not even done that.”

The agency argued that CME has been telling investors that it hasn’t heard of a demand for perps and that they aren’t substitutes for the futures it’s offering.

“CME cannot have it one way with the court and another way with the investing public on earnings calls,” the CFTC contended in its brief.

Jaret Seiberg, a policy analyst at TD Cowen, argued in a Monday client note that CME may still have the edge, in both its standing as a competitor and its argument that perps may be appropriately treated as swaps. However, the clock is ticking on the new market.