With Palantir’s stock plummeting more than 11% this week despite a better-than-expected earnings report, CEO Alex Karp took aim at investors betting against the software company.

Karp, who co-founded Palantir in 2003, went after short sellers in two separate interviews on CNBC this week. After “Big Short” investor Michael Burry revealed bets against Palantir and Nvidia, Karp on Tuesday accused short sellers of “market manipulation.”

He repeated that message on Friday in an interview with CNBC’s Sara Eisen, again knocking Burry’s wager against the stock.

“To get out of his position, he had to screw the whole economy by besmirching the best financials ever … that are helping the average person as investors [and] on the battlefield,” Karp said.

Even with Palantir’s slide this week, the stock is up 135% in 2025 and has multiplied 25-fold in the past three years, an extended rally that’s lifted the company’s market cap to over $420 billion. While revenue and profit are growing rapidly, the multiples have shot up much faster, and the stock now trades for about 220 times forward earnings, a ratio that rivals Tesla’s.

Nvidia and Meta, by contrast, have forward price-to-earnings ratios of about 33 and 22, respectively.

In August, Citron Research’s Andrew Left, a noted short seller, called Palantir “detached from fundamentals and analysis” and said shares should be priced at $40. It closed on Friday at $177.93 after late-day gains pushed the stock into the green.

Palantir, which builds analytics tools for large companies and government agencies, reported earnings and revenue on Monday that topped analysts’ estimates and issued a forecast that was also ahead of Wall Street projections.

But the stock fell about 8% after the report and then slid almost 7% on Thursday. Karp told Eisen that the recent boom in Palantir’s share price isn’t just for Wall Street.

“We’re delivering venture results for retail investors,” he said.

While Palantir has in the past faced a fairly heft dose of short interest, there are currently relatively few investors placing big bets against it. The short interest ratio, or the percentage of outstanding shares being sold short, peaked at over 9% in September and is now at a little over 2%, which is about as low as its been since the company went public in 2020.

Still, calling out the doubters is a common occurrence for Karp, who has previously said on CNBC that people should “exit” if they “don’t like the price.”

In May, after the stock plummeted following earnings, Karp said ,”You don’t have to buy our shares.”

“We’re happy,” he said. “We’re going to partner with the world’s best people and we’re going to dominate. You can be along for the ride or you don’t have to be.”

The company has also faced backlash over its work with government agencies like U.S. Immigration and Customs Enforcement, and Karp has admitted that his strong pro-Israel stance led some people to leave the company.

The boisterous CEO has been particularly vocal this week. On Monday’s earnings call, he questioned how happy the people are who didn’t invest in the company, and told them to “get some popcorn.”

And on CNBC he aimed much of his ire at Burry after the investor revealed his short positions in Palantir and Nvidia.

“The two companies he’s shorting are the ones making all the money, which is super weird,” Karp told CNBC’s “Squawk Box” on Tuesday. “The idea that chips and ontology is what you want to short is bats— crazy.”

WATCH: Palantir CEO Karp on short sellers

In this Club Check-in, CNBC’s Paulina Likos and Zev Fima break down big tech’s massive artificial intelligence spending spree — debating whether these billion-dollar bets will drive long-term cost savings or weigh on near-term returns.

Mega-cap tech companies are shelling out billions of dollars to build out AI infrastructure. The big question we’re asking is whether all this heavy spending will eventually pay off in efficiency or if Wall Street is right to worry about how much they’re burning through in the short term.

Concerns about AI-stock valuations seeped into the market this week and slammed stocks.

Many major tech companies —including the three biggest clouds, Amazon, Microsoft, and Alphabet‘s Google — raised capital expenditure guidance this earnings season, sparking both investor optimism and concern.

Zev Fima, portfolio analyst for the Club, argued the spending is justified: “Too much focus on the short-term is what leads to falling behind in the long term.” CNBC reporter Paulina Likos pushed back, noting that “investors haven’t seen efficiency gains show up in returns yet.”

Watch the video above to see where the debate played out on whether AI investments are real productivity drivers or just expensive promises until proven otherwise.

(See here for a full list of the stocks in Jim Cramer’s Charitable Trust, the portfolio used by the CNBC Investing Club.)

As a subscriber to the CNBC Investing Club with Jim Cramer, you will receive a trade alert before Jim makes a trade. Jim waits 45 minutes after sending a trade alert before buying or selling a stock in his charitable trust’s portfolio. If Jim has talked about a stock on CNBC TV, he waits 72 hours after issuing the trade alert before executing the trade.

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Affirm CEO Max Levchin said Friday that while the buy now, pay later firm isn’t seeing credit stress among federally employed borrowers due to the government shutdown, there are signs of a change in shopping habits.

“We are seeing a very subtle loss of interest in shopping just for that group, and a couple of basis points,” Levchin told CNBC’s “Squawk on the Street.”

At least 670,000 federal employees have been furloughed in the shutdown, and about 730,000 are working without pay, the Bipartisan Policy Center said this week.

Levchin said he’s closely watching employment data for signs of major disruptions, but the company is “capable” of adjusting credit standards when needed.

“Right now, things are just fine,” he said. “We’re not seeing any major disturbances at all.”

The federal funding lapse, which began Oct. 1, is the longest in U.S. history and has halted work across agencies with an impact beyond those who are government employees. The SNAP food benefit program, which serves 42 million Americans, has also been cut off.

The comments from Levchin followed a fiscal first-quarter earnings report that blew past Wall Street’s estimates. Affirm posted earnings of 23 cents per share on $933 million in revenue. Analysts polled by LSEG expected earnings of 11 cents per share on $883 million in sales.

Revenues climbed 34% from a year ago, while gross merchandise volumes jumped 42% to $10.8 billion from $7.6 billion a year ago. That surpassed Wall Street’s $10.38 billion estimate.

The fintech company, which went public in 2021, also lifted its full-year outlook, saying it now expects gross merchandise volume to hit $47.5 billion, versus prior guidance of $46 billion.

Affirm also said it renewed its partnership with Amazon through 2031. The company has also inked deals with the likes of Shopify and Apple in a competitive e-commerce landscape.

Long-time partner Walmart recently ditched Affirm for Swedish buy now, pay later firm Klarna, which went public in September after delaying its public offering due to market uncertainty caused by President Donald Trump‘s tariff plans. Worries of a pullback in discretionary spending due to tariffs ignited fears across the fintech sector.

Levchin said categories such as ticketing and travel have seen an uptick in interest, and consumer shopping remains strong. Active consumers grew to 24.1 million from 19.5 million a year ago.

“We’re every single day out there preaching the gospel of buy now, pay later being the better way to buy, and consumers are obviously responding,” he said.