If the trader is buying, the order is matched with existing sell orders (asks) at the lowest available ask price. trade99 review If the trader is selling, the order is matched with existing buy orders (bids) at the highest available bid price. Traders must be aware of regulations from key oversight bodies such as FINRA and the SEC to stay in compliance. These regulations ensure transparency, fairness, and accountability in trading. Pattern day traders—those making at least four day trades within five business days—must