low 50.6%241 sessions, all (<1y) · today 63.3%high 116.5%
Term structure · constant maturity
31 consecutive sessions in contango (the normal upward slope).
━ 2026-09-18┅ 2026-08-19 (21 sessions earlier)◆ scheduled release, at the first tenor spanning it■ earnings, at the first session it can move (□ no expected move served)tenors in calendar days, log scale
Scheduled after the 2026-09-18 close, from the 2026-09-18 calendar snapshot (forecasts as they stood then). Each is marked with the shortest tenor, in calendar days, that spans it:
Fri 09-25 10:00 · 7d U. Michigan Final Consumer Survey (September) · prev 51.7
Earnings: 2026-10-29 time unknown, stated by the vendor's estimate, first moves the 2026-10-29 session (41d on the tenor axis), no expected move served. As the vendor's calendar stood on 2026-09-21, not on the page's date.
90-day IV
67.3%
own all (<3y) 9.3% · n=241
slope, 30d − 90d
-4.0 pts
own all (<3y) 20.5% · n=241
variance risk premium, 30d
+22.6 pts
own all (<3y) 89.2% · n=236
Skew · risk reversal
25-delta
-5.9 pts
own all (<3y) 4.3% · n=35
10-delta
-7.1 pts
own all (<3y) 12.9% · n=35
Skew has been collected since 2026-07-30 only: the vendor serves no earlier history, so each percentile here is taken over all of it - the few weeks of readings there are, which the n beside it counts.
Smile by expiry: the 8 expiries within 120 DTE carrying the most open interest · book as of 2026-09-17
1d2026-09-18 · short
8d2026-09-25
15d2026-10-02
22d2026-10-09
29d2026-10-16
64d2026-11-20
92d2026-12-18
120d2027-01-15
IV against strike, out-of-the-money side. Each window widens with √DTE, to ±25% at the longest expiry, so every panel shows a comparable slice of its smile; all share one IV scale (60%–73%), set by the expiries past 7 DTE. 1 short-dated point beyond it is pinned to the edge as an open circle.
Expiry window · 35–65 DTE
Next earnings: 2026-10-29 time unknown, stated by the vendor's estimate, first moves the 2026-10-29 session, no expected move served. As the vendor's calendar stood on 2026-09-21, not on the page's date.
DTE counts calendar days from 2026-09-18, the page's date and the earliest an entry could be made - not from the 2026-09-17 book the expiries and IVs come from, which would overstate it by 1 day; an expiry first listed after 2026-09-17 is not in the book and not here. A premarket report moves its own session and a postmarket one the next; one with no stated time is placed at the earlier of the two - or at the later, once the earlier is already in the 2026-09-18 close - so an expiry can be called spanning when it might not be, never the reverse. "spans +N": the expiry settles N calendar days after that session, and the line under it says whether the 28-DTE exit comes before it ("inside the exit": that date is already behind 2026-09-18, so it protects nothing); "clear N": it settles N days before it. Thesis = DTE − 28 (the hard exit is 21), cut to the last session before a report that comes first. Every expiry in the band is listed, and one that is not a third Friday is marked weekly — §1 of the trading rules admits no weeklies and no 0DTE, so those rows are context, not candidates; the mark is the calendar test on the date alone, and a monthly pulled back to a Thursday by a holiday carries it too. ATM IV is the vendor's at the 2026-09-17 close, on the out-of-the-money side of the listed strike nearest book spot: a display selection, not a statistic, read at that one strike, so "no IV at X" is about X and not about its neighbours. The expected move is the vendor's, for the report the expiry spans. Every row links to that expiry on the strike axis below.
Chain · one strike axis
Book as of 2026-09-17: 1 session behind 2026-09-18: no WDC chain statistics (net_gex) dated after 2026-09-17 are knowable as of 2026-09-18, and no ticker has newer ones. The strikes drawn below are 2026-09-17's rows as stored now; the levels and statistics are the readings dated 2026-09-17, computed from those rows when the readings were derived, and a fetch of 2026-09-17 after that can revise rows. Open interest is what entered 2026-09-17 (OCC's settlement of 2026-09-16), valued at the 2026-09-17 close.
net GEX · carried book
-$21.9m per 1%
own all (<3y) 14.8% · n=64
gamma flip
$444.20
flip within ±25% of book spot
flip distance
+0.89 ATR
own all (<3y) 75.4% · n=63
0DTE share of volume
not listed daily
book spot $423.87 (unadjusted close, 2026-09-17) · call wall $400.00 (-5.63% from book spot) · put wall $420.00 (-0.91% from book spot) · max pain $450.00 (+6.16% from book spot, 2026-10-16 monthly)
Each level is stored as a distance from the book's own spot, so each is drawn at $423.87 × (1 + that distance) - the 2026-09-17 unadjusted close, the price the chain was taken at. That is why two prices appear on this page. WDC headlines $441.36, its newest unadjusted close, on 2026-09-18; the book was taken at $423.87 on 2026-09-17, because the book trails the page by the one session counted above. Both are closes, both are dated, and neither is adjusted. Recomputing a wall on the newer close would put it at a level this book never had, so none of these is: they are the 2026-09-17 book's levels, on the 2026-09-17 close.
Dashed: 7 DTE or less, where the vendor's gamma is noisy. "mp": the monthly max pain describes.
Tradability of the 2026-10-23 expiry: 35 calendar days from 2026-09-18 (36 from the book date), inside the owner's 35–65 DTE entry window. Spreads are the NBBO stored with the 2026-09-17 chain snapshot - not a live quote, and not DESIGN J's quote at a trade (per-trade quotes are not collected) - as a percent of mid; a zero or missing bid, or a crossed quote, is drawn as × for no two-sided quote. The owner's floors are marked and filter nothing: spread 10% of mid, OI 500 (no strike drawn reaches 500 on either side, before or after 2026-09-16's trading, so that line is off the panel), and the strike nearest 0.20 delta on each side - call 515 (Δ 0.20), put 365 (Δ -0.19).
call put OI carried through 2026-09-16 · opened by 2026-09-16's trading · closed by it / net GEX long / short gammabook spotcall wallput wallmax paingamma flipfloors, marked not filtered: spread 10% of mid · OI 500 · ▸◂ strike nearest 0.20 delta, beside the spread panel · × no two-sided quote · | spread past 25%
2026-10-23 expiry, 41 strikes within ±25% of book spot (the flip search band); 39 hidden (32 above, 7 below), 34 of them with open interest. One row per listed strike: rows are evenly spaced, prices are not. Net GEX is this expiry's alone (-$481k per 1% in all); the walls, flip and headline sum every carried expiry. Volume is 2026-09-17's own - whether it opened positions shows in the 2026-09-18 book's change.
max pain $450.00 belongs to the 2026-10-16 monthly (29 days from 2026-09-17, as max_pain_expiry_dte stores it: the nearest monthly at least 7 days out), not to this expiry.