Definition. The number of open, not-yet-closed futures contracts at the end of the day. It differs from volume, which counts all trades made.
How it works
When a new buyer and a new seller open a position, open interest rises by one contract. When both sides close their positions, it falls. The exchange publishes it once a day.
Example
During the roll, open interest in the expiring contract falls and in the next one it rises.
What to watch out for
Interpreting changes in open interest together with price can help with the broader context, but it gives no signals on the scale of a single session.
You'll find the full explanation with graphics, examples and exercises in the 🖥️ Order flow atlas space, and its use in the live market in the 🔴 Live Room. Both are available to Club members (in Polish).
