Daily fantasy sports (DFS) are a fast-paced variant of traditional fantasy sports, where players build teams under a salary cap and earn points based on real-world athlete performance, but contests last just a day or a week instead of a full season. The industry was long dominated by the New York-based FanDuel and Boston-based DraftKings, which together controlled 95% of the U.S. market and were valued at over $1 billion each by 2015, thanks to heavy venture capital backing and aggressive marketing. DFS faced intense legal scrutiny because many states considered it a form of illegal sports betting, leading to lawsuits and investigations, such as the 2015 New York probe into insider information, though by December 2017, 18 states had declared it a game of skill. The landscape shifted dramatically in 2018 when the U.S. Supreme Court struck down the Professional and Amateur Sports Protection Act in Murphy v. NCAA, allowing states to legalize sports betting and prompting FanDuel and DraftKings to pivot into bookmaking. In the years that followed, the market diversified with new operators like Atlanta-based PrizePicks (founded 2015) offering simplified "pick'em" contests, which grew rapidly and operated in dozens of states, including some without legal sports betting. However, starting in 2023, regulators in several states began scrutinizing these house-backed pick'em products, forcing some operators to alter their contest structures or exit certain markets.