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Open Interest

OVERVIEW

Open interest (OI) is the count of options or futures contracts at a specific strike and expiration that remain open at the end of the trading day — contracts that have been opened but not yet closed, exercised, or expired.

Note

For US equity options, exchanges compute OI overnight from the OCC's morning position file. Any figure displayed during the trading day reflects the prior session's close, not the current session.

OI is a stock, not a flow. If a contract changes hands between two existing holders, OI is unchanged even though volume increments. Volume measures total contracts traded in a session; OI measures net contracts still alive at the close.

HOW OPEN INTEREST CHANGES

Every options trade involves a buyer and a seller, each either opening or closing a position. The combination of those intents determines whether OI rises, falls, or holds steady.

Buyer Action Seller Action OI Effect Interpretation
Opens Opens +1 New contract created
Closes Closes −1 Contract extinguished
Opens Closes No change Position transfers to a new long
Closes Opens No change Position transfers to a new short

Tip

When daily volume exceeds OI, fresh positioning is being built. When volume is a small fraction of OI, the existing book is churning between holders rather than growing.

WORKED EXAMPLE

Orderly session — SPY

The SPY June 19 2026 $550 call closed on 2026-04-17 with OI of 45,200. On 2026-04-21 it traded 12,400 contracts of volume and OI rose to 46,100, a net +900. Of the 12,400 trades, 11,500 were position transfers and only 900 represented net-new contracts — a modest, orderly session.

Directional surge — GME

A GME $40 weekly call trades 50,000 contracts on a Monday starting from OI of 2,000 and closes at OI of 48,000. That is fresh, directional positioning: retail piling in, dealers writing exposure, and gamma being built into the book.

Note

The GME pattern above is characteristic of setups that feed gamma squeeze dynamics, where dealer hedging flow snowballs into forced buying of the underlying.

FEATURES

Tapeboard surfaces open interest data across the following analytical workflows.

Feature How OI Is Used
Dealer GEX Models Aggregate OI by strike, weight by gamma, infer where market-maker hedging flow buys or sells the underlying
Max-Pain Analysis Identify the strike at which aggregate OI value (calls + puts) is minimized at expiration — a magnet for pin-risk expirations
Unusual Activity Screens Flag daily volume greater than prior OI at out-of-the-money strikes as potential fresh speculation or informed positioning
Liquidity Assessment High-OI contracts tend to carry tighter bid-ask spreads and absorb larger orders with less slippage
Futures Roll Timing Track OI shifting between front and back months to time calendar rolls in commodity and index futures

HOW TO USE

Reading the OI column

OI displayed in Tapeboard's options chain reflects the prior night's OCC-confirmed figure. It updates once per day after the market close.

Interpreting intraday OI estimates

Tapeboard's real-time dashboard may display estimated intraday OI derived from tape analysis. These are model estimates, not OCC-confirmed figures.

Note

Treat intraday OI estimates as directional signals only. Confirm positioning with end-of-day OCC data before drawing conclusions.

Spotting unusual activity

  1. Open the Options Flow screen.
  2. Filter for contracts where Volume > Prior OI.
  3. Narrow to out-of-the-money strikes for the highest-signal unusual prints.
  4. Cross-reference with the GEX heatmap to assess dealer exposure at that strike.

Avoiding calendar distortions

OI drops sharply at expirations and roll dates by construction. When comparing week-over-week OI, account for the expiration calendar — particularly around the third Friday of each month — to avoid false signals.

Tip

Use Tapeboard's expiration-adjusted OI view to strip out roll-driven OI collapses before performing trend analysis.

LIMITATIONS

Limitation Detail
Once-daily publication OI is never truly live; intraday figures are always estimates
Direction unknown High OI does not reveal who is net long or short — a 50k-OI call could be 50k retail longs or 50k market-maker longs
Not a liquidity guarantee A contract can carry high OI and wide spreads if a single dormant holder accounts for most of it
Calendar distortion OI collapses at expirations and roll dates; week-over-week comparisons require calendar adjustment