Financial markets/Financial markets : The Stock Market

Overview
Various types of securities are traded on the stock market, for example, common stocks, debentures, convertible debentures and bonds. Trading is closely regulated. Securities newly issued by companies seeking investment capital are sold in what is known as the primary market. These securities may be offered directly by the company seeking investments or by a securities firm, or brokerage, acting as an agent. Previously issued securities, already in circulation among investors, are bought and sold in the secondary market. The companies that initially issued these securities receive no cash from trade in the secondary market—the instruments simply change hands from one investor to another.
The Stock Exchange of Thailand (SET) is a secondary market, important to Thai investment and financial markets. It serves as the central exchange for buying and selling securities and is a mechanism for channeling excess funds held by investors into needed manufacturing capital. As a result, savings and investments are put to effective use. There is also the Market for Alternative Investment, or MAI securities market, for capital accumulation for small and medium enterprises in export industries, in industries that the government has chosen to support for the sake of economic recovery and for growth industries.
The SET Index is a market capitalization weighted statistical measure reflecting changes in overall stock prices relative to a benchmark price. The SET50 and SET100 indices were implemented in 2005 to reflect the stock prices for the largest 50 and 100 companies, in terms of size and liquidity, listed on the SET. They are calculated in the same way as the SET index and the list of included companies is revised every six months according to a specified formula.
The total amount traded on the SET (not including the MAI) was about 4.3 trillion Baht in 2009, a daily average of 18 billion Baht. Factors influencing the SET indices include, for example, the economy, fluctuations in indices of stock markets abroad and interest rates. About 61 percent of investors on the SET in 2009 were individual Thai nationals, 19 percent, 13 percent, and 7 percent were foreign investors, proprietary trading, and institutional investors, respectively.