A couple of charts from UBS:
UBS reckons this is reason for a restock. In the new normal of oversupply, 6 weeks of port supply and 26 days of mill supply is masses of ore to do just the opposite. Combined that equals about 8 weeks of consumption.
It takes nine days to ship iron ore from the Pilbara and about a month from Brazil. Why would you hold more than 60 days?