Shipping rates have seen the largest seasonal drop in over half a decade as global events coupled with typical trading patterns to hinder earnings, the world's largest shipbroker says.

Sarah Holden, an analyst at Clarksons, said the cross-sector ClarkSea index was down 40% from its December peak to the trough seen in the middle of February.

Holden explained the swing was not unprecedented, with similar percentage drops recorded 2014 and 2016.