Loading the player... Covariance is a measure of the degree to which returns on two risky assets move in tandem. A positive covariance means that asset returns move together, while a negative covariance means returns move inversely.
1. Rotterdam (the Netherlands) This Dutch harbor was the largest in the world, until Shanghai and Singapore grew even larger in 1986. This satellite photo gives an indication of the size of the Port of Rotterdam. (Image via Mannlines) About an hour and a half to the south of Rotterdam is Antwerp, the largest port in Belgium.
Shanghai International Port, China. The Shanghai harbor opened in 1842 as a treaty port. It faces the East China Sea to the east and Hangzhou Bay to the south. Back in the early 20th century, Shanghai became not only the largest city in the Far East, but the largest port too.