In what might be the most surprising collaboration to hit the prediction markets scene, the CEOs of Kalshi and Polymarket, two companies locked in an intense battle for dominance, are putting aside their differences to back a new $35 million venture capital fund. Yeah, you read that right. These competitors are actually investing together.

The fund, called 5© Capital (named after the regulatory clause governing prediction markets, if you’re curious), was launched by former Kalshi employees and is already attracting major players. Beyond the two rival CEOs, heavy hitters like Marc Andreessen and Ribbit Capital founder Micky Malka are throwing their support, and money, behind the initiative.

Kalshi CEO Tarek Mansour confirmed his involvement, though Polymarket CEO Shayne Coplan remained quiet when asked about his investment. The fund is being led by Adhi Rajaprabhakaran, a former Kalshi trader, and Noah Zingler-Sternig, who previously headed operations at Kalshi.

So what’s the play here? 5© Capital is looking to back founders who want to capitalize on the “second-, third-, and fourth-order effects” of the prediction markets boom. Translation: they’re not just betting on prediction markets themselves, but on all the businesses that can build around them. The fund plans to invest in about 20 companies, with a focus on infrastructure, think market makers and index designers, that support the broader ecosystem.

This move comes as both Kalshi and Polymarket are experiencing explosive growth and valuations. Kalshi is currently raising $1 billion at a $22 billion valuation, which is pretty wild considering the company was valued at $11 billion just four months ago. That’s a straight-up doubling. Meanwhile, Polymarket is in its own funding conversations, reportedly eyeing a $20 billion valuation.

The partnership between these two rivals is honestly kind of fascinating. These companies have had some genuinely bitter moments, there was even that time when Kalshi’s CEO admitted to using influencers to trash-talk Polymarket on a now-deleted podcast segment. So the fact that both are willing to invest in the same fund suggests they’re thinking bigger picture. Maybe they realize that the prediction markets space is still so early that there’s plenty of room for both of them to succeed while also betting on a whole wave of new companies building in the space.

It’s a reminder that even in the startup world’s most heated rivalries, business is business. When the opportunity is right, competitors can still find common ground, especially when there’s money and market potential involved.