Options Skew Analytics

AON options analytics

AON · Stock

Data as of 24 September 2026 (end of day)

No metrics could be computed for this session

Its next earnings report is 2026-10-28 (estimated from its reporting cadence).

Across its last 3 reports the options market priced an average move of ±7.0% and AON moved 4.5% on average, staying inside the priced band 2 times out of 3.

Current readings

30-day ATM implied volatilityⓘ
—
25-delta risk reversalⓘ
—
25-delta butterflyⓘ
—
Term structure slopeⓘ
—

Where 30-day implied volatility sits

Against 11 prior sessions (one-year window)

Not enough history in this window to place the current reading.

IV percentile, 1 year
—
IV rank, 1 year
—
IV percentile, 2 years
—
IV rank, 2 years
—

Rank is the position between the lowest and highest readings in the window, so a single past extreme pins everything after it near one end. Percentile is the share of sessions below the current reading and is unaffected by how far that extreme reached. Both are withheld when the window holds fewer than 180 sessions.

Session detail

Underlying close
$276.09
30-day implied forward
—
60-day ATM IV
32.49%
90-day ATM IV
31.29%
180-day ATM IV
30.62%
Expirations used
4
Total open interest
5,341
Put / call open interest
8.35

The forward is derived from put-call parity on the strikes nearest the money, not taken from the underlying close. It is what every moneyness and delta on this page is measured against.

30-day at-the-money implied volatility

Last 234 sessions

16%18%20%22%24%26%28%2024-09-19 — 30-day ATM IV 18%2024-10-17 — 30-day ATM IV 23%2024-10-18 — 30-day ATM IV 23%2024-10-21 — 30-day ATM IV 23%2024-10-22 — 30-day ATM IV 24%2024-10-23 — 30-day ATM IV 24%2024-10-24 — 30-day ATM IV 24%2025-01-23 — 30-day ATM IV 22%2025-01-28 — 30-day ATM IV 27%2025-02-20 — 30-day ATM IV 17%2026-09-21 — 30-day ATM IV 27%19 Sep21 Oct23 Oct28 Jan21 Sep
Show the underlying numbers (most recent 120)
Session30-day ATM IV25-delta RRTerm slopeClose
2026-09-24———$276.09
2026-09-23———$281.60
2026-09-22———$286.10
2026-09-2126.81%+0.691.044$290.82
2026-09-18———$295.64
2026-09-17———$296.05
2026-09-16———$300.57
2026-09-15———$304.67
2026-09-14———$311.54
2026-09-11———$302.69
2026-09-10———$307.77
2026-09-09———$304.69
2026-09-08———$315.79
2026-09-04———$323.09
2026-09-03———$327.00
2026-09-02———$330.88
2026-09-01———$326.30
2026-08-31———$321.52
2026-08-28———$355.40
2026-08-27———$349.56
2026-08-26———$353.98
2026-08-25———$354.83
2026-08-24———$359.10
2026-08-21———$355.11
2026-08-20———$351.93
2026-08-19———$348.43
2026-08-18———$343.20
2025-06-30———$356.76
2025-06-27———$352.73
2025-06-26———$353.55
2025-06-25———$354.46
2025-06-24———$360.68
2025-06-23———$359.95
2025-06-20———$354.70
2025-06-18———$350.83
2025-06-17———$350.81
2025-06-16———$350.04
2025-06-13———$353.00
2025-06-12———$355.78
2025-06-11———$349.48
2025-06-10———$351.71
2025-06-09———$353.83
2025-06-06———$371.09
2025-06-05———$370.49
2025-06-04———$372.62
2025-06-03———$374.48
2025-06-02———$376.16
2025-05-30———$372.08
2025-05-29———$366.92
2025-05-28———$361.32
2025-05-27———$365.06
2025-05-23———$356.54
2025-05-22———$355.33
2025-05-21———$358.06
2025-05-20———$362.43
2025-05-19———$364.96
2025-05-16———$361.92
2025-05-15———$358.59
2025-05-14———$352.22
2025-05-13———$355.07
2025-05-12———$353.57
2025-05-09———$354.32
2025-05-08———$357.11
2025-05-07———$359.72
2025-05-06———$357.93
2025-05-05———$355.49
2025-05-02———$356.25
2025-05-01———$351.54
2025-04-30———$354.79
2025-04-29———$349.90
2025-04-28———$343.47
2025-04-25———$335.85
2025-04-24———$365.05
2025-04-23———$368.83
2025-04-22———$368.52
2025-04-21———$355.95
2025-04-17———$367.41
2025-04-16———$372.82
2025-04-15———$379.11
2025-04-14———$384.34
2025-04-11———$376.30
2025-04-10———$369.02
2025-04-09———$373.37
2025-04-08———$360.23
2025-04-07———$364.35
2025-04-04———$375.76
2025-04-03———$394.29
2025-04-02———$396.03
2025-04-01———$398.81
2025-03-31———$399.09
2025-03-28———$394.55
2025-03-27———$399.54
2025-03-26———$396.73
2025-03-25———$396.14
2025-03-24———$393.15
2025-03-21———$390.35
2025-03-20———$393.17
2025-03-19———$390.38
2025-03-18———$390.05
2025-03-17———$390.98
2025-03-14———$398.79
2025-03-13———$394.20
2025-03-12———$398.29
2025-03-11———$399.74
2025-03-10———$398.99
2025-03-07———$403.09
2025-03-06———$401.60
2025-03-05———$404.07
2025-03-04———$404.68
2025-03-03———$409.32
2025-02-28———$409.12
2025-02-27———$404.00
2025-02-26———$399.23
2025-02-25———$397.57
2025-02-24———$392.18
2025-02-21———$389.56
2025-02-2017.07%+0.931.111$393.07
2025-02-19———$394.87
2025-02-18———$391.09
2025-02-14———$386.99

The chart covers every session in the archive, 234 in total. The table lists the most recent 120.

25-delta risk reversal

Last 234 sessions

-1.00.01.02.03.04.02024-09-19 — 25-delta RR (volatility points) 3.52024-10-17 — 25-delta RR (volatility points) 3.52024-10-18 — 25-delta RR (volatility points) 2.72024-10-21 — 25-delta RR (volatility points) 3.32024-10-22 — 25-delta RR (volatility points) 2.82024-10-23 — 25-delta RR (volatility points) 3.32024-10-24 — 25-delta RR (volatility points) 2.62025-01-23 — 25-delta RR (volatility points) 1.32025-01-28 — 25-delta RR (volatility points) 2.52025-02-20 — 25-delta RR (volatility points) 0.92026-09-21 — 25-delta RR (volatility points) 0.719 Sep21 Oct23 Oct28 Jan21 Sep

The dashed line marks zero, where the 25-delta put and call carry the same implied volatility.

Skew curve

Implied volatility by delta, front expirations

Implied volatility by delta

57d (2026-11-20) · 85d (2026-12-18) · 113d (2027-01-15)

29%30%31%32%33%34%2026-11-20 (57d) — 15Δ C — IV 31.82%2026-11-20 (57d) — 20Δ C — IV 31.75%2026-11-20 (57d) — 25Δ C — IV 31.53%2026-11-20 (57d) — 30Δ C — IV 31.42%2026-11-20 (57d) — 35Δ C — IV 31.53%2026-11-20 (57d) — 40Δ C — IV 31.74%2026-11-20 (57d) — 45Δ C — IV 32.25%2026-11-20 (57d) — ATM — IV 32.70%2026-11-20 (57d) — 45Δ P — IV 32.90%2026-11-20 (57d) — 40Δ P — IV 33.01%2026-11-20 (57d) — 35Δ P — IV 32.96%2026-11-20 (57d) — 30Δ P — IV 32.85%2026-11-20 (57d) — 25Δ P — IV 32.98%2026-11-20 (57d) — 20Δ P — IV 33.68%57d2026-12-18 (85d) — 25Δ C — IV 31.67%2026-12-18 (85d) — 30Δ C — IV 31.60%2026-12-18 (85d) — 35Δ C — IV 31.44%2026-12-18 (85d) — 40Δ C — IV 30.78%2026-12-18 (85d) — 45Δ C — IV 30.88%2026-12-18 (85d) — ATM — IV 31.32%2026-12-18 (85d) — 45Δ P — IV 31.25%2026-12-18 (85d) — 40Δ P — IV 31.08%2026-12-18 (85d) — 35Δ P — IV 31.23%2026-12-18 (85d) — 30Δ P — IV 31.63%2026-12-18 (85d) — 25Δ P — IV 32.46%2026-12-18 (85d) — 20Δ P — IV 32.77%85d2027-01-15 (113d) — 20Δ C — IV 31.15%2027-01-15 (113d) — 25Δ C — IV 30.33%2027-01-15 (113d) — 30Δ C — IV 30.30%2027-01-15 (113d) — 35Δ C — IV 30.74%2027-01-15 (113d) — 40Δ C — IV 30.98%2027-01-15 (113d) — 45Δ C — IV 31.13%2027-01-15 (113d) — ATM — IV 31.21%2027-01-15 (113d) — 45Δ P — IV 31.02%2027-01-15 (113d) — 40Δ P — IV 30.24%2027-01-15 (113d) — 35Δ P — IV 30.49%2027-01-15 (113d) — 30Δ P — IV 30.93%2027-01-15 (113d) — 25Δ P — IV 31.07%2027-01-15 (113d) — 20Δ P — IV 32.23%113d10Δ C25Δ CATM25Δ P10Δ Pout-of-the-money calls ← delta → out-of-the-money puts

The axis is call delta. Readings to the right of the dashed centre line are taken from the out-of-the-money put at that strike, which is the contract whose quote the volatility was solved from. Points are only plotted where surviving quotes bracket the delta on both sides; nothing is extrapolated past the last traded strike.

Show the underlying numbers
Delta57d85d113d
15Δ call31.82%——
20Δ call31.75%—31.15%
25Δ call31.53%31.67%30.33%
30Δ call31.42%31.60%30.30%
35Δ call31.53%31.44%30.74%
40Δ call31.74%30.78%30.98%
45Δ call32.25%30.88%31.13%
ATM32.70%31.32%31.21%
45Δ put32.90%31.25%31.02%
40Δ put33.01%31.08%30.24%
35Δ put32.96%31.23%30.49%
30Δ put32.85%31.63%30.93%
25Δ put32.98%32.46%31.07%
20Δ put33.68%32.77%32.23%

Wing readings by expiration

ExpirationDaysForwardATM IV25Δ put25Δ callRRButterflyQuotes
2026-11-2057$277.5832.70%32.98%31.53%+1.46-0.448
2026-12-1885$278.0331.32%32.46%31.67%+0.78+0.759
2027-01-15113$278.9931.21%31.07%30.33%+0.74-0.5210
2027-04-16204$282.0530.50%31.12%30.20%+0.92+0.1613

Each curve above is one expiration. The vertical position is implied volatility; the horizontal position is the delta of the contract it was read from. For US equities the curve normally slopes upward to the right, meaning out-of-the-money puts carry higher implied volatility than equidistant calls.

The 25-delta risk reversal summarises that slope as a single number: the 25-delta put volatility minus the 25-delta call volatility. The butterfly summarises the curvature: the average of the two wings minus the at-the-money reading.

Term structure

At-the-money implied volatility by expiration

At-the-money implied volatility by expiration

4 listed expirations produced a usable reading

30%31%32%33%2026-11-20 — 57 days — at-the-money IV 32.70%2026-12-18 — 85 days — at-the-money IV 31.32%2027-01-15 — 113 days — at-the-money IV 31.21%2027-04-16 — 204 days — at-the-money IV 30.50%6090180days to expiration

The horizontal axis is the square root of days to expiration, which is the scale volatility lives on. A curve that is flat in variance terms plots as a straight line here rather than bending sharply through the front week.

Show the underlying numbers
ExpirationDaysForwardATM IVATM strikeQuotes used
2026-11-2057 days$277.5832.70%$279.918
2026-12-1885 days$278.0331.32%$281.229
2027-01-15113 days$278.9931.21%$283.2310
2027-04-16204 days$282.0530.50%$289.4813

Constant maturities

Interpolated between the bracketing listed expirations, in total variance

30 days
—
60 days
32.49%
90 days
31.29%
180 days
30.62%

Interpolation is linear in total variance, not in volatility. Interpolating volatility directly implies a forward variance that can be negative between two expirations. A tenor beyond the longest listed expiration is reported as unavailable rather than extrapolated.

Term structure slope

Last 234 sessions

0.700.800.901.001.101.202024-09-19 — 90-day over 30-day 1.102024-10-17 — 90-day over 30-day 0.832024-10-18 — 90-day over 30-day 0.882024-10-21 — 90-day over 30-day 0.842024-10-22 — 90-day over 30-day 0.822024-10-23 — 90-day over 30-day 0.842024-10-24 — 90-day over 30-day 0.842025-01-23 — 90-day over 30-day 0.862025-01-28 — 90-day over 30-day 0.832025-02-20 — 90-day over 30-day 1.112026-09-21 — 90-day over 30-day 1.0419 Sep21 Oct23 Oct28 Jan21 Sep

The dashed line marks 1.00, where the 90-day and 30-day at-the-money volatilities are equal. Above it the longer tenor carries the higher volatility.

The term structure is the at-the-money implied volatility of each listed expiration, plotted against how far away that expiration is. Its usual shape for a calm underlying slopes gently upward, because a longer horizon admits more uncertainty.

It inverts when the market prices a dated event: an expiration that captures a scheduled announcement carries the variance of that event on top of ordinary trading, so a shorter contract can print a higher volatility than a longer one.

Earnings

What the options priced in before each report, and what happened

Next report

2026-10-28Time not statedEstimated from its reporting cadence

How the pricing has held up

Over the last 3 reports

Landed inside the implied band
2 of 3
67% — about 68% is what an exactly-priced event gives
Mean implied move
7.0%
Mean move that happened
4.5%
absolute

Reports

Newest first. The implied move is one standard deviation, priced from the session before the release.

ReportSessionImplied ±RealisedRealised / implied
2026-07-29Before the open———
2026-05-01Before the open———
2026-01-30Before the open———
2025-10-31Before the open———
2025-07-25Before the open———
2025-04-25Before the open7.9%-8.0%1.01×
2025-01-31Before the open6.9%-0.4%0.05×
2024-10-25Before the open6.3%+5.2%0.83×
2024-07-26Before the open———
2024-04-26Before the open———
2024-02-02Before the open———
2023-10-27Before the open———

The implied move is read from the at-the-money straddle on the first expiration strictly after the report date, converted to a one-standard-deviation move and divided by the forward. Realised moves are the close-to-close return across the event, measured from the session before the release to the session after it.

Report dates that have already happened come from the company’s own 8-K filing and are exact. A date still in the future is either one the company has announced, or an estimate from its reporting cadence.