First Binance then OKX have clamped down on prime brokers who offer their clients lower fees. As the world's largest cryptocurrency exchanges crack down on brokerage firms that have bundled together clients to take advantage of lower trading fees, some market participants are warning the move could harm markets. Binance was the first to prevent prime brokers from leveraging its multitiered fee system to lower their own costs and offer rebates to clients, making changes to its Link Plus interface last month.