Explain why it might be preferable for a person to invest in a portfolio of securities rather

Question:

Explain why it might be preferable for a person to invest in a of securities rather than in a single security.

Portfolio
A portfolio is a grouping of financial assets such as stocks, bonds, commodities, currencies and cash equivalents, as well as their fund counterparts, including mutual, exchange-traded and closed funds. A portfolio can also consist of non-publicly...