Basically cancelling is this -
I contract to deliver 30,000 pounds of bananas on Oct 31st for $30,000. You hold the other end of that contract.
October 31st rolls around and those bananas are worth $50,000. What do you want, $50,000 or 15 tons of bananas. Usually, paying out the contract at current market price is the simplest solution all around. Then you can contact fruits-r-us and have the necessary bananas delivered where you want them. Considering the extra costs of handling and storing commodities, unles you are a banana warehouse, cash is preferable.
If I get a “buy” contract to match the “sell” then for me, bananas = 0.
Futures are for 2 purposes. Farmers, for example, want a guaranteed price up front for what they will produce - helps pay for seed, fertilizer etc. BUyers - restaurants, grocery stores, want to know they will have a steady supply of pork bellies at a reliable price. The exchange connects the two.
Like every other trade, then everyone else gets in on the act and start making extra contracts. Anyone can promise to sell you something if you want to buy. Of course, if they promise to deliver bananas and don’t have the goods, they better have the cash to make good on their promise whatever the current market price. Not sure what he guarantees required by the Exchange are against default, but there’s some sort of backing to ensure you don’t just walk away and tell the other side, “sorry, no bananas and no money”.
Then there’s options, just for fun. I will pay you for the right to buy or to not buy a contract to deliver at $X, say 30,000lb of bananas for Oct 31st for $50,000. I will decide by Oct 25th. If I choose not to (price of bananas has gone up, delivering those bananas will cost more than $50,000) then the option expires. If by Oct 25 it looks like I can buy bananas on the 31st for $30,000 then I exercise the option, get a contract that you will buy them for $50,000, presto- $20,000 profit unless there’s a deep freeze in Central American before Halloween.
This is much like a real estate option - I will pay you $1,000 for the right to buy your house in the next 6 months for $500,000. If I choose not to, you keep the $1,000 and house, but I haven’t taken on a $500,000 mortgage if I decide by then the house is not worth it.
Since the price of commodities can fluctuate wildly, it is the quickest way to lose your shirt. However, options either expire worthless or you can get a healthy payout.