Grain is stored in warehouses until needed for milling or shipment.
When we speak of _December wheat_ we mean wheat that is to be
delivered to the buyer in December. The carrying charges include
storage, interest, and insurance, so that wheat sold for _May
delivery_ would necessarily bring a higher price than wheat sold for
December delivery. Carrying charges are in favour of the _short_
seller. When sold for immediate delivery it is known as _cash grain_.