Stocks are listed on a specific exchange, which brings buyers and sellers together and acts as a market for the shares of those stocks. The exchange tracks the supply and demand and directly related, the price of each stock. The share holders are the owners of the company. The share holders initially get their shared through IPO. Stock market is the place where buyers and sellers are exchanging their stocks. The spot price of the shares are usually decided by the buyers and sellers. Thus it is driven by demand and supply. SEBI is the regulatory authority for the stock market. Markets depend on company performance and Companies are not affected by share prices.