Abstract:
Capital is one of the worlds scarce resources. It is also an essential factor input on a par with land, labour, management, and (more recently) energy. Without it no businesses can start or continue operation. Owing to these facts, there have been established many financial institutions to mobilize long-term funds from the public for various business concerns. One of these is the capital or securities market. In the case of Thailand, one such market began in 1953. Sales and Transactions of shares, however, were very small. Despite the establishment of the Bangkok Stock Exchange in 1964, the situation did not improve. The bearish condition of the market could be due to the fact that share transactions are a novelty for Thais and that most people lack proper understanding of investment in securities. There are other problems too like those of an economic and political nature, including the fact that economic development has not attained its projected growth rate. As things developed, it has become apparent that the Bangkok Stock Exchange has failed in its fund mobilizing capacity. The failure has turned out to be a boon, however, in turning the governments attention to actively promoting a capital market. In 1969, an expert was invited from the U.S.A., in the person of Professor Sidney M. Robbins, to study the feasibility (as well as other aspects of the project) of a securities market in this country. In 1974, capping Robbins efforts, the Securities Exchange of Thailand Act was promulgated. A year later, on April 30, the Securities Exchange of Thailand (SET) started operations. Though SET has fared somewhat better than its predecessor, the Bangkok Stock Exchange, it nonetheless is far from being bullish. Furthermore, its operative scope is still very restricted, with a limited number and type of securities being transacted therein. Sale of stocks is conducted among a few groups, average daily turnovers amounting to roughly Baht 4-5 million. SET has to weather too the economic and political ups and downs which bear direct repercussion on investors decisions. Besides, the lack of proper understanding and the absence of basic decision principles are still prevalent today, resulting in the fact that the public dares not risk its savings in investing in securities. The purpose of this thesis is to lend support to SET. Through it, it is hoped, the participation of the public in the capital market in this country will increase. The topic Choice of portfolio investment as prevailing at the Securities Exchange of Thailand has been chosen. This treatise is intended to aid those who desire to invest in common shares to do so with well-founded principles, instead of as it were gambling or initiating others. The investors decision principles are based on the expected rate of return and the share risk. Through these, the return on portfolio investment may be approximated, which will help increase the efficiency of investment. This study is based on data made available by SET. It begins with the risk of and the return on various securities and the factors affecting them. Through least square regression model, the rate of return of each security and that of the market are derived. This study confines itself to roughly 5 active stocks calculating the risk percentage rate which affects them. It determines the proportion of portfolio investment in order to find the efficient frontier of investment which is used as the investors decision principle. With the public understanding investment methodology better on top of the fact, that an additional number of public companies will hopefully be registered at SET, both the demand and supply of securities would then increase, rendering SET more active. With this modest help, it is hoped that SET will come a step closer to realizing its goal of being the mobilizing centre of long-term capital for businesses ultimately leading to the countrys successful economic development.