The popular prediction market Polymarket has raised $300 million from 1789 Capital as part of a new funding round totaling around $1 billion, The Wall Street Journal reported, citing unnamed sources.

1789 Capital, an investment fund in which Donald Trump Jr. is a partner, previously invested $200 million in the prediction site. The firm has funded other controversial tech-related projects, including the Enhanced Games, the so-called “steroid Olympics” founded by veterans of various tech companies.

TechCrunch has reached out to Polymarket for comment.

Prediction markets have come under increased regulatory scrutiny, as many state governments seek to institute new rules around how (or even if) the sites can be used by residents. There are at least 20 states engaged in litigation against prediction sites over sports wagers offered on those sites.

The federal government, meanwhile, has frequently sought to defend the prediction industry from state regulation. The Trump administration has argued that the sole regulator of the industry should be the Commodity Futures Trading Commission (CFTC), not state governments. The CFTC has sued at least nine states over their attempts to regulate the industry.

A coalition of 44 state attorneys general recently signed a letter arguing that the CFTC does not have the authority to regulate sports-related wagers on prediction sites.

The New York Times has reported that Donald Trump Jr. recently appeared at an event involving conservative state attorneys general, where he described the prediction industry as already having “robust oversight” and characterized prediction sites as a tool “overseen by federal officials, not state attorneys general.”