From the very old days economic systems in parallel with having physical facilities have been trying to utilize various instruments to equip their resources and direct these resources towards effective production activities and make profit.

    Now a days in most of the industrial the countries  development of the financial sector has created a situation in which we are witnessing new financial instruments within the different economic regimes around the globe . to take the advantag of the maximum available resources of the country.

One of these tools which has been used in most of the developing countries during the recent few decades are investment companies which are in the form of public companies . in order to equip financial resources .

This group of companies because of their special nature practically decrease the risk of investment and therefore have been welcomed by the public in a way that  based on some unofficial estimations almost half of the value of listed stock in the exchanges belongs to these companies .

Investment companies are among the active financial institution within the capital market .By collecting small capitals of the public and through issuance of stocks these companies  invest in profit making activities especially  in stocks and other securities ,Therefore by diversification they are able to reduce the risk of investment and at the same time provide their investors with a reasonable return .

This dissertation is based on this hypothesis and is trying to study whether we can suggest investing in the stock investment companies as an investment which provides investors with reasonable return and a low risk or not .

Another the point worth mentioning about the importance of these companies  is that such companies can play an important role in pricing and stock valuation and eventually  lead the market towards more efficiency .Therefore these companies are providers of a major part of financial resources flowing to securities exchanges and are of great importance in the capital markets .

In this dissertation ,by doing a case study on  a petrochemical investment company as one of these investment companies it has been tried to find an answer for this question  that  whether this company was able to create a suitable portfolio in a way that not only absorb small capitals but also provide a low risk with suitable return investment opportunity for investors . In other word whether buying the stocks of Petrochemical investment companies could be a proper replacement and alternative investment choice  for stocks of other companies or not.

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