XBI open interest — latest available snapshot
XBI options open interest totalled 239,075 contracts across 7 expirations, settled on 2026-08-31 · XBI (the SPDR S&P Biotech ETF) · front expiry 2026-09-04: 10,022 puts vs 5,207 calls · last price $161.87 on 2026-09-01
Latest available snapshot — open interest settled on 2026-08-31. This is a dated positioning read, not a live number. The static page is rebuilt nightly from the latest upstream chain available; intraday volume does not move open interest until the next settlement.
What did the 2026-08-31 snapshot show?
XBI carried 239,075 open option contracts across the 7 listed expirations inside 45 days. The front expiration, 2026-09-04, held 15,229 of them — 10,022 puts against 5,207 calls, a put/call ratio of 1.93. The heaviest single call strike (the call wall) sat at $168, +3.8% from the last price, and the heaviest put strike (the put wall) at $161, -0.5% away. Open interest counts open contracts, not intent: every contract has a buyer and a seller.
Heaviest strikes — 2026-09-04
The ten strikes holding the most combined open interest for the front expiration, among strikes within 15% of the max pain level (the window our nightly pipeline reports).
| Strike | Call OI | Put OI | Total |
|---|---|---|---|
| $161 | 455 | 1,772 | 2,227 |
| $163 | 449 | 1,426 | 1,875 |
| $158 | 14 | 1,297 | 1,311 |
| $168 | 894 | 275 | 1,169 |
| $160 | 114 | 857 | 971 |
| $165 | 348 | 540 | 888 |
| $164 | 254 | 496 | 750 |
| $155 | 44 | 577 | 621 |
| $159 | 18 | 529 | 547 |
| $170 | 365 | 87 | 452 |
How concentrated is XBI open interest?
The 2026-08-31 snapshot's top-ten figure for XBI applies only to the headline 2026-09-04 expiration and only to the 55 reported strikes within 15% of max pain; it is not full-chain concentration. The wall-to-wall distance was 4.3% of the settled last price and also belongs to that expiration. Only the expiration-share figures use all 239,075 contracts across the 7 listed expirations inside 45 days. Read the wall distance as a same-expiration strike gap, and the expiration shares as how the reported chain's contracts were distributed across listed expirations. Chain-wide, the 2026-09-18 expiration was the largest bucket, holding 71.1% of the 239,075 contracts counted across the 45-day window. Every figure is derived from open-interest counts — what open interest measures, and how it differs from volume explains how those counts are created, destroyed and settled once a day. A crowded strike means many contracts exist there; it does not mean price is drawn to it or repelled by it. Before assigning meaning to either wall, read our guide to what call and put walls can — and cannot — tell you; it explains why a crowded strike is a concentration marker, not support, resistance or a price target.
XBI open interest by expiration
| Expiration | Call OI | Put OI | Total | Call wall | Put wall |
|---|---|---|---|---|---|
| 2026-09-04 | 5,207 | 10,022 | 15,229 | $168 | $161 |
| 2026-09-11 | 1,475 | 8,330 | 9,805 | $168 | $159 |
| 2026-09-18 | 70,614 | 99,298 | 169,912 | $155 | $150 |
| 2026-09-25 | 2,776 | 862 | 3,638 | $167 | $155 |
| 2026-10-02 | 653 | 757 | 1,410 | $165 | $150 |
| 2026-10-09 | 25 | 258 | 283 | $170 | $135 |
| 2026-10-16 | 22,401 | 16,397 | 38,798 | $185 | $149 |
The same XBI chain, other lenses
These counts feed every other XBI page here. XBI max pain turns them into the settlement price that would pay option holders the least — that page also charts this distribution strike by strike; XBI put/call ratio tracks the puts-to-calls balance daily; XBI gamma exposure estimates dealer positioning against the same book.
Common questions
How much XBI open interest was outstanding in the latest snapshot?
Using open interest settled at the close on 2026-08-31, XBI carried 239,075 option contracts across the 7 listed expirations inside 45 days. The front expiration, 2026-09-04, held 15,229 of them: 10,022 puts and 5,207 calls.
What is open interest?
Open interest is the number of option contracts that exist and have not yet been closed, exercised or expired. It is not trading volume: a contract that changes hands ten times in a day still counts once. Every contract has a buyer and a seller, so open interest says how many positions are open, not which side anyone is on.
What are the XBI call wall and put wall?
They are simply the strikes holding the most call and put open interest for an expiration — $168 and $161 respectively in this snapshot. The count says where contracts are concentrated; whether price respects those levels is a separate empirical question the count itself cannot answer. The guide at quantdata.uk/guides/call-wall-put-wall explains how to read them without treating them as support or resistance.
Is XBI open interest concentrated in a few strikes?
In the 2026-08-31 snapshot the ten heaviest strikes held 71.7% of the 15,082 contracts inside the reported window — the 55 strikes within 15% of max pain that we publish, not the full chain. The put wall sat at $161 and the call wall at $168, 4.3% apart measured against the last price. Chain-wide, 2026-09-18 was the heaviest of the 7 listed expirations at 71.1% of all 239,075 contracts. These are contract counts. They show concentration, not whether price will be attracted to or repelled by a strike.
When does XBI open interest update?
The clearing house settles open interest once per trading day, after the close. This page is rebuilt nightly from that end-of-day file, so no figure here — or anywhere — is a live intraday open-interest reading.