Mattress Mack turns to Kalshi for $13M Astros bet

Jim "Mattress Mack" McIngvale is backing the Houston Astros to win another World Series, but this time his massive wager is not with a traditional sportsbook.

McIngvale has put $516,000 on Houston through prediction market Kalshi, with a potential payout of $13 million if the Astros win the 2026 World Series, according to the New York Post.

The longtime Astros bettor said Kalshi helped connect him with market makers who offered him a price equivalent to around 24/1, compared with approximately 18/1 available at sportsbooks after Houston clinched its playoff spot.

Why Mattress Mack turned to Kalshi

McIngvale's wager serves as a hedge against a Gallery Furniture promotion that promises refunds to customers who spend at least $4,000 if the Astros win the World Series.

He told the Post that the promotion already carries approximately $4 million in liability, which could grow to around $12 million if Houston makes a deep postseason run.

"I had a price in mind for the hedge, and the sportsbooks were about 18/1 after they clinched, and I wanted to get higher than that," McIngvale said. "I talked to Kalshi, and they connected me with these market maker guys, and they got me the price of 24/1."

The choice of Kalshi is particularly notable because McIngvale is based in Texas, where traditional online sports betting remains illegal.

Kalshi operates as a federally regulated prediction market and offers sports event contracts in Texas, allowing McIngvale to establish the position without traveling to a state with legal sports betting.

It also gives him the ability to trade out of the position before the World Series is decided if he chooses to adjust his exposure.

Mattress Mack could face $12 million liability

McIngvale has used major sports wagers for years to offset the risk created by Gallery Furniture promotions.

His most famous payoff came when the Astros won the 2022 World Series, generating approximately $75 million in betting winnings while triggering tens of millions of dollars in customer refunds.

"The last time the Astros won, we gave back $74 million," McIngvale said. "Some people got refunded $70,000 back."

The strategy doesn't necessarily guarantee Gallery Furniture a profit. McIngvale said transaction costs, including credit card fees associated with customer refunds, can significantly reduce the benefit of the hedge.

Kalshi offers another route for sports hedging

McIngvale's decision provides a high-profile example of how sports prediction markets can compete with sportsbooks for large positions, particularly in states without legal online sports betting.

Kalshi Director of Business Development Nicolas Hull said competition between counterparties on the exchange helped McIngvale secure a better price for his hedge.

"That's the advantage of an exchange, where price discovery happens through competition," Hull told the Post. "When counterparties compete, the cost of hedging comes down and business owners get a better deal."

McIngvale was also asked about the growing competition between prediction markets and traditional sportsbooks.

"I can whine about my competition, or I can put on my big boy britches and go out there and beat 'em," he said.

Now his attention turns back to the Astros, who will host the Chicago White Sox in Game 2 of their Wild Card series on Wednesday, needing a win to keep their postseason alive after falling 6-3 in the series opener.

Dimers' MLB model gives Houston a 61.6% chance of forcing a deciding Game 3, compared with a 38.4% chance of Chicago completing the sweep. For Mattress Mack, an Astros win would also keep his $13 million potential Kalshi payout alive.