The order placed by Buyer/Seller is taken by the Broker who in turn pass on to the stock exchange and when the Buyer/Seller quoted price is matched then the trade is executed. SEBI acts as regulation body for transparency through out. Stock trading can potentially yield high return when risks are mitigated properly. The stock exchange ensures trader counter party is not at risk. Buyer and Seller determines the stock price and stock trading is business if Risk to Reward is purely understood and a clear trade plan is must prior initiating any trade.