The Securities and Exchange Board of India (Sebi) on Thursday debarred Ketan Parekh, the stock market operator involved in the stock market scam of 2000, Singapore-based trader Rohit Salgaocar, and one other individual from the securities market for alleged front-running of trades of a United States (US)-based foreign portfolio investor (FPI).The FPI manages around $2.5 trillion worth of funds globally.