“You have a backdrop of very strong commodity demand, globally," Mavrinac told CNBC.

"And once you got past the iron ore negotiations back in March and April, you saw a surge in activity of iron ore heading towards China such that it created quite a bit of busy ships right now."

But Mavrinac cautioned that the indicator doesn't necessarily measure broad-based global economic strength, as the surge is primarily driven by China.

Sourced from www.cnbc.com