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.
It is classed as a lake, and is the world's largest, with an area of 371,800 km2 and a maximum depth of 184 metres. The Caspian Sea is rich on oil and gas. The biggest cities by the Caspian Sea are the Russian port city Astrakhan and the capital of Azerbaijan, Baku. 1  Comment the question.  Wikipedia.