The Baltic Exchange's main sea freight index, tracking rates for ships carrying dry bulk commodities, jumped to a more-than-three-month high on Wednesday, as rates for capesize vessels soared. The overall index, which also factors in rates for panamax, supramax and handysize shipping vessels, ended up 35 points, or 3.15 percent, at 1,147 points, its highest since Dec. The capesize index increased 207 points, or 10.73 percent, to close at 2,136 points, its biggest gain since early December.