The dry bulk spot market posted a one-week slump on Friday as torrential rains kept a lid on Brazilian iron ore exports, dragging capesize spot rates down.

The capesize 5TC, a spot-rate average weighted across five key routes, dropped to $12,407 per day, according to Baltic Exchange data. That was a seven-day drop of 38.5%.

"Weather is always the issue in Q1, and I expect this to remain the driving force behind capesize rates," said John Kartsonas, founder of Breakwave Advisors' dry bulk ETF-trading platform.