Wiktionary
n. (context finance English) The total number of contracts outstanding between market participants in a market for futures, options, or other derivatives.
Wikipedia
Open interest (also known as open contracts or open commitments) refers to the total number outstanding of derivative contracts that have not been settled (offset by delivery).
For each buyer of a futures contract there must be a seller. From the time the buyer or seller opens the contract until the counter-party closes it, that contract is considered 'open'.
Open interest is the number of "open" contracts of derivatives like futures and options that have a time limit after which they expire. Open interest in a derivative is the sum of all contracts that have not expired, been exercised or physically delivered. Moreover, the open interest is the number of long positions or, equivalently, the number of short positions.
Usage examples of "open interest".
As James ate, Dancing Cloud watched Beauregard Smythe with open interest.
She was aware of Paige watching them with open interest, alerted perhaps by the difference in Evie’.
She was aware of Paige watching them with open interest, alerted perhaps by the difference in Evies manner from the way she usually treated customers.
Flinn moved his mount away, but Adley was too focused on staring through the rain to notice anything so near, and Dashiva, still wiping his face incessantly, stared with open interest.
Brutus eyed her with open interest and she returned his gaze without embarrassment.
Quentin silenced the Chief of Supply with a gesture, conscious of the open interest of the others.
I turned back to Dee after my survey of the building to find that her open interest had attracted a particularly insistent crowd of the black-and-white robes.
And they carried with them a group's brash confidence, eying the girls with open interest, and swaggering when they walked.
Soon after the Northmen entered the house, some of them began to display an open interest in the valuables that were casually on display.
And they both turned, McCoy distracted from his intent, to find Spock watching them with open interest.
He made no pretence of listening to the lecture, but he observed the audience with open interest.