When you buy/sell
a futures contract, you ar obliged to deliver or take delivery of the goods when the contract expires.

So, if today you buy a December OJ contract, you are obliged to take delivery of xx tonnes (or whatever) of OJ, in December.

But, if tomorrow you sell an OJ contract, you are obliged to deliver the same to whoever bought it.

The exchange though, will nett out your position. You have bought one, and sold one, therefore your position is zero.

You can hold your long/short position until the contract expires. This can be many months ahead.

So the trick is, to buy low, and sell high, or sell high, then buy low. Unless you;re actually wanting a shitload of frozen orange juice, you always need to nett out your position before the contract expires.
(username failed moderation, Fri 14 Oct 2011, 13:10, 1 reply)

piggies
I did hear of one futures trader in pork bellies who forgot to settle, and got a surprisingly large delivery of pigs one morning.
(Simian Typewriter Supplies Pty. Ltd. is house hunting in the neighborhood of infinity, Fri 14 Oct 2011, 14:06, closed)

There are a few stories like that.
We had a girl in the office who forget to close out a small position in sugar futures.

Conversation went something like;

"Here, I've got the excange on the phone, say we've got to take delivery of 50 tons of sugar"

"Who fucking did that??"

"Jackie did. What do I tell this bloke??"

"Tell him to take it round and dump it in her fucking garden"
(username failed moderation, Fri 14 Oct 2011, 14:15, closed)