The presidential campaign of Vivek Ramaswamy is halting its TV advertising in the crucial final stretch leading up to the first nominating contests in January, arguing its resources are better used elsewhere as the first-time candidate lags behind several rivals in polls of the Republican race.

The unusual move stirred some speculation that Ramaswamy might drop out and endorse former president Donald Trump, the overwhelming polling leader in the GOP race, whom Ramaswamy — more than any of his rivals — has defended and emulated. But his campaign said it was not pulling back on spending and sought to project optimism about its future.

Ramaswamy and his team said they simply were ditching an ineffective medium and retooling for the stretch run before the mid-January Iowa caucuses, even as they did not explicitly rule out the possibility of bowing out. “Big surprise coming on Jan 15,” Ramaswamy wrote on X, formerly Twitter, noting, “We’re doing it differently.”

Trump himself weighed in Tuesday on his social media site, Truth Social. “He will, I am sure, Endorse me,” he said of Ramaswamy. “But Vivek is a good man, and is not done yet!”

Once a little-known entrepreneur, Ramaswamy seized the spotlight at the first GOP debate in August and struck a chord with some in the Republican base. But he also proved polarizing and didn’t translate the interest into sustained momentum in early nominating states such as Iowa and New Hampshire, where Trump’s challengers need to make a splash. Ramaswamy is mired in the single digits in polls, with the long-shot fight to displace Trump increasingly boiling down to former U.N. ambassador Nikki Haley and Florida Gov. Ron DeSantis.

Tens of millions in TV advertising from Trump’s opponents has yet to dent his large lead in the primary, a fact Ramaswamy highlighted in his statement on X.

“Presidential TV ad spending is idiotic, low-[return-on-investment] & a trick that political consultants use to bamboozle candidates who suffer from low IQ,” Ramaswamy wrote.

NBC News first reported the suspension of TV spending.

Campaign spokeswoman Tricia McLaughlin said their “spending levels haven’t changed — we’re just following the data. We are focused on bringing out the voters we’ve identified — best way to reach them is using addressable advertising, mail, text, live calls and doors to communicate with our voters on Vivek’s vision for America, making their plan to caucus and turning them out.”

Asked about suggestions Ramaswamy might drop out soon, McLaughlin echoed the candidate: “Get ready for a major upset on January 15.”

Ramaswamy’s campaign has spent more than $4.6 million on advertising tracked by the firm AdImpact, which monitors investments in television, radio and digital commercials. The bookings ramped up in October and November but then tapered off quickly in December, with about $112,000 spent the week of Dec. 12 and just over $5,000 the week of Dec. 19. AdImpact lists no Ramaswamy ads booked after that.

His rivals and their allied super PACs are spending heavily on TV as the Iowa caucuses approach, often attacking one another.

A pro-DeSantis super PAC beset by turmoil, Never Back Down, recently canceled all of its planned television advertising in Iowa and New Hampshire, but officials suggested this was part of shifting roles among the groups supporting DeSantis.

DeSantis’s campaign has signaled that it wants Never Back Down to stick to field organizing while a newer group handles advertising and assails Haley. And yet another outside group supporting DeSantis, called Good Fight, popped up last week and has reported spending more than $1.8 million on media placement promoting him.