WASHINGTON — In an effort to demonstrate good faith ahead of next week's expected Senate vote on the Sanders-Ocasio-Cortez AI moratorium bill, the chief executive of one of the country's largest hyperscalers told a Senate panel on Sunday that his company had already begun "voluntarily pausing" a wide range of activities, including several it was not engaged in and a few it has not yet conceived of.

Trevor Halsey, the chief executive of Helion Compute, appeared before a rare Sunday session of the Senate Commerce, Science, and Transportation Committee, where he opened his testimony by submitting into the record what he described as "a comprehensive list of the things Helion is no longer doing, beginning effective immediately and, in some cases, retroactively."

The list, which ran to 14 pages, included the pausing of frontier model training runs that had not been initiated, the suspension of data center construction at sites that had not been zoned, and the indefinite postponement of "any research direction a reasonable person could one day find concerning."

"Helion Compute hears the American people," Halsey said in prepared remarks. "We are pausing. We are pausing harder than any of our competitors. In some cases, we are pausing activities our competitors have not yet announced, in order to demonstrate that we will pause them first."

Halsey was joined at the witness table by the chief executives of three other hyperscalers, each of whom submitted similar lists. Together, the four companies confirmed they were collectively standing down from an estimated 11,400 initiatives, of which independent analysts said roughly 30 appeared to exist.

Sen. Bernie Sanders, the bill's lead Senate sponsor, pressed Halsey on whether Helion would also pause the activities the company is in fact engaged in, including the construction of three gigawatt-scale data centers in Texas, Virginia, and central Wyoming. Halsey said the company was prepared to "review" those activities under a framework Helion has internally designated "Strategic Continuance."

"Strategic Continuance is the principled commitment to continuing the things that, on reflection, should continue," Halsey told the committee. "It is the natural complement to our voluntary pause, and together the two frameworks ensure that nothing inappropriate is taking place at Helion Compute, regardless of what is taking place."

Sen. Ed Markey, who has co-sponsored the bill in the Senate, asked Halsey to clarify whether any of Helion's actual products fell under the scope of the voluntary pause. After a brief consultation with counsel, Halsey said that they did not, but that the company had paused "the version of those products that would have been concerning."

"We are now shipping only the reassuring version," Halsey said.

The hearing was the latest stop in an unusually intense lobbying push by the major AI firms, which over the past two weeks have flooded Capitol Hill with executives, white papers, and what one Senate staffer described as "approximately one cocktail reception per hallway." The Senate is expected to vote on the moratorium bill on Tuesday, with the outcome considered close.

In her opening statement, Sen. Maria Cantwell, the committee's chair, noted that the executives' decision to appear on a Sunday afternoon spoke to the seriousness with which the industry was treating the legislation. Halsey, in his response, said the timing had been chosen "to convey humility, and also to avoid the news cycle."

Several other industry figures offered similar testimony. The chief executive of Numina Systems, Priya Bhatt, told the panel that her company had voluntarily ceased "the training of any model that, in retrospect, we would prefer not to have trained." Asked whether such a model existed, Bhatt said the company was "not in a position to confirm or deny the existence of models that, by definition, we are no longer training."

Marcus Field, the chief executive of the cloud and infrastructure provider Rivulet, said his firm had agreed to pause "the build-out of any data center capacity beyond what is required to serve our customers, our customers' customers, and reasonable projections of future need." Rivulet's most recent quarterly filing projects future need to grow 41 percent year over year.

The fourth executive, Helen Park of the AI safety-aligned firm Conjoint, told the committee that her company had "already been pausing, in spirit, since founding," and asked whether the legislation could include language formally recognizing this.

The hearing also drew testimony from outside experts. Dr. Aaron Yusupov, a senior fellow at the Brookings Institution who studies AI governance, told the committee that the executives' commitments, while well-intentioned in tone, appeared to bind the companies to "no activity in particular, on no timeline in particular, with no enforcement of any kind."

"What we are witnessing is the industry pausing the pause," Yusupov said. "It is a kind of recursive forbearance, in which each commitment refers to a prior commitment that does not exist."

Asked by Sen. Josh Hawley whether Helion Compute would support the moratorium bill if it passed, Halsey said the company was "supportive of the values the bill represents" and would continue to be supportive of those values "in whatever form they ultimately take, including the form in which they do not become law."

Halsey added that Helion remained committed to working with Congress on a "voluntary, industry-led, externally observed, internally implemented framework for responsible non-action," and said the company would publish a one-page summary of that framework at a date to be determined by the framework itself.

The committee adjourned shortly before 7 p.m. without a vote. A spokesperson for Sen. Sanders said the senator considered Sunday's testimony "instructive" and intended to "proceed accordingly."

In a brief statement to reporters as he left the Hart Senate Office Building, Halsey said Helion Compute remained "open to dialogue" and would announce additional voluntary pauses as needed, including, if circumstances required, a pause on announcements.