A growing legal clash is unfolding between Native American tribes and Silicon Valley-backed prediction markets, as tribal leaders warn that new forms of online wagering threaten the economic backbone of Indigenous communities across the U.S.

According to Bloomberg, a coalition of Native American organizations and tribes has filed a legal brief backing the Ho-Chunk Nation of Wisconsin in its lawsuit against Kalshi and Robinhood.

These companies undermine a hard-won system that has allowed tribes to fund essential government services, social programs, and economic development through gaming revenue, the Native nations argue.

The decision marks an escalation of a broader fight over the future of prediction markets. The brief, supported by groups including the Indian Gaming Association and the National Congress of American Indians, maintains that gaming is not simply a commercial activity for tribes but an existential one tied directly to tribal sovereignty and self-determination.

Tribes have historically dominated gaming outside Las Vegas due to legal carve-outs allowing gambling on Indigenous land, creating a critical revenue stream. They contend that Kalshi and Robinhood’s offerings bypass these protections and violate longstanding law. Kalshi maintains that its regulation by the Commodity Futures Trading Commission overrides state and tribal authority, while Robinhood says its products operate within a compliant framework.

Despite mounting legal resistance from tribes and states such as Nevada, prediction markets continue to gain traction. Competitors like Polymarket are striking media partnerships, and major exchanges, including Intercontinental Exchange and CME Group, are moving into the space—signaling that the regulatory battle is only beginning.