Seattle tech leaders have warned that a proposed income tax proposal could hinder the region's progress in artificial intelligence. The group of AI researchers, founders, and investors have urged state leaders to halt work on the "millionaires tax", a state income tax that would impose a 9.9% levy on personal income above $1 million, and an increase to Washington’s capital gains tax. They argue that higher taxes on high earners and investment gains would push top talent and future startups elsewhere. The letter also highlights a potential AI competitiveness issue, stating that Washington is losing momentum compared to other hubs. The proposed income law, Senate Bill 6346, was approved by the state Senate earlier this month and is currently being debated by House lawmakers.