Regulation ATS, or Alternative Trading System, is a set of rules established by the Securities and Exchange Commission (SEC) to govern trading platforms that facilitate the buying and selling of securities outside traditional exchanges. These regulations aim to enhance transparency and protect investors by requiring ATS operators to register and provide specific disclosures about their operations. Under Regulation ATS, these trading systems must adhere to certain operational standards, including reporting trades and maintaining fair access for all participants. This regulation helps ensure that alternative trading venues operate in a manner that promotes market integrity and investor confidence.