It’s January 1st and you’re a farmer that is trying to plan your business for the rest of the year. With current estimates, you think your orange trees will produce 50 bushels, worth $5000. However, there was a late freeze last year which destroyed half of your crops. You’re concerned that this could happen again so you want to find a way to hedge your risk. You draw up a contract that represents rights to all of the oranges that your trees have grown by June 30th and look for a buyer. Someone might buy your contract for several reasons. First is that you might be willing to sell the contract for less than $5000 but more than $2500. This would protect you from the kind of downside you faced the year before, while if everything goes as predicted the buyer will make the difference between $5000 and the price of the contract. A second possibility is that the buyer of the contract believes the price of oranges will increase by the time of harvest, making the 50 bushels worth $6000 instead. Similarly, they could also expect the price to remain the same but the trees to produce more than 50 bushels. In all three situations, you hedge your risk by collecting your money up front, while the buyer takes on some risk over a longer time horizon for more benefit. The buyer of the contract can freely trade it afterwards as well, and many trading opportunities can occur as people have different opinions on how many oranges will be harvested and/or what the price of oranges will be in 6 months.
A month later, you decide that you want to get out of orange farming all together. You’ve already promised the oranges that will be grown are owed to the holder of the first contract, so you can’t sell your trees immediately. Instead, you draw up another contract, which entitles someone to all the trees in your orchard on July 1st. To make up for the time that they won’t be able to take possession of the trees, you sell the trees for less than they would be worth at current market value. In this situation, you free up capital early to reinvest into something else, while the buyer gets a discount on the trees they want, as long as they’re willing to be a little patient. In this situation too, the buyer can trade their contract as they see fit, and the final holder will be the one that takes possession of the trees on the date of expiration.
When generalized, you can call the orange trees the principal, and the oranges themselves the yield. Any asset that passively accrues some value can have this framework applied to it, as people use their own assumptions and modeling to determine how much income an asset will generate and how to value both that income and the asset itself.