What are the key benefits of a company investing and trading securities

What are the key benefits of a company investing and trading securities. Explain the rationale.What are the potential benefits of the domestic securities market to those investing in the foreign securities markets. Provide specific examples to support response. Justify the importance of investment diversification. Explain the rationale.
Suggest how a financial analyst would determine if the reward of a given investment outweighs the risk. Support with examples.

Need 2 references and in text cites.