Why is the variance of a portfolio of internationally diversified stocks likely to be lower than the

Question:

Why is the variance of a of internationally diversified likely to be lower than the variance of a of U.S. Stocks
Stocks or shares are generally equity instruments that provide the largest source of raising funds in any public or private listed company's. The instruments are issued on a stock exchange from where a large number of general public who are willing... 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...