Aon plc

AON · Insurance Agents, Brokers & Service · 213.6M shares · -4%/yr ↓ buyback · EDGAR filings ↗

Net buyback after stock comp: $1.1B (gross $1.6B, SBC $438M)

Reference price $329.72 · est. market cap ~$70.4B — last insider sale, 2026-02-26 (estimated from the dated SEC Form 4 price × shares outstanding — not a live quote)

Grade

A83

Aon — premier global insurance broker/advisory with elite returns.

Strengths

ROE 39.5% (81st pct), operating margin 25% (86th)
Recurring, capital-light brokerage model
Strong free cash flow (90th)

Risks

High leverage (D/E 1.6, 88th)
Acquisition-integration (NFP) risk
Cyclical advisory demand

Notable findings

Exec changeRecent 8-K item 5.02 8-K ↗
Insider buyingInsider buying — 1 open-market buy(s) by 1 insider(s) (~$1M, last 6mo) Form 4 ↗
Buying back stockNet buyback — share count -4%/yr over 4y
Insider sellingInsider selling — 2 open-market sale(s) by 1 insider(s) (~$3M, last 6mo) Form 4 ↗

Quarterly revenue

2025-06-30 · $4.2B2025-09-30 · $4.0B2025-12-31 · $4.3B2026-03-31 · $5.0B

Last 4 quarters · from SEC filings.

Key metrics

Operating margin

25.3%

Net margin

21.5%

Return on equity

39.5%

Return on assets

7.3%

ROIC

13.9%

Revenue growth (QoQ)

17.1%

Net-income growth

39.2%

Debt / equity

1.6×

Current ratio

1.1×

Free cash flow

$3.2B

Tangible book value

-$12.2B

Cash & investments

$3.0B

Stock comp / revenue

2.5%

Insider transactions · last 18 months

Date	Insider	Type	Shares	Price
2026-05-12	NOTEBAERT RICHARD C	Gift	1.4K	—
2026-03-13	Corona Anne	Option exercise	193	—
2026-03-13	Corona Anne	Tax withheld	85	$321.41
2026-03-13	Corona Anne	Option exercise	174	—
2026-03-13	Corona Anne	Tax withheld	77	$321.41
2026-03-13	Goltermann Lori	Option exercise	228	—
2026-03-13	Goltermann Lori	Tax withheld	99	$321.41
2026-03-13	Goltermann Lori	Option exercise	290	—
2026-03-13	Goltermann Lori	Tax withheld	126	$321.41
2026-03-13	Marcell Andy	Option exercise	1.2K	—
2026-03-13	Marcell Andy	Tax withheld	568	$321.41
2026-03-13	Marcell Andy	Option exercise	464	—
2026-03-13	Marcell Andy	Tax withheld	226	$321.41
2026-02-26	Zeidel Darren	Sell	4.3K	$329.72
2026-02-19	Case Gregory C	Gift	7.5K	—
2026-02-19	Case Gregory C	Gift	7.5K	—
2026-02-19	Case Gregory C	Gift	11K	—
2026-02-19	Case Gregory C	Gift	11K	—
2026-02-19	Case Gregory C	Gift	11K	—
2026-02-19	Case Gregory C	Gift	11K	—
2026-02-18	Stevens Lisa	Gift	32	—
2026-02-17	Case Gregory C	Option exercise	2.4K	—
2026-02-17	Case Gregory C	Tax withheld	1.0K	$325.96
2026-02-17	Case Gregory C	Gift	3.2K	—
2026-02-17	Case Gregory C	Gift	3.2K	—
2026-02-17	Case Gregory C	Gift	3.2K	—
2026-02-17	Case Gregory C	Gift	3.2K	—
2026-02-17	Zeidel Darren	Sell	5.0K	$325.79
2026-02-13	Simon Mindy F.	Option exercise	254	—
2026-02-13	Zeidel Darren	Option exercise	871	—
2026-02-13	Zeidel Darren	Tax withheld	386	$321.70
2026-02-13	Zeidel Darren	Option exercise	209	—
2026-02-13	Zeidel Darren	Tax withheld	93	$321.70
2026-02-13	Stevens Lisa	Option exercise	1.5K	—
2026-02-13	Stevens Lisa	Tax withheld	701	$321.70
2026-02-13	Stevens Lisa	Option exercise	478	—
2026-02-13	Stevens Lisa	Tax withheld	231	$321.70
2026-02-13	Simon Mindy F.	Tax withheld	109	$321.70
2026-02-13	Reese Edmund	Option exercise	598	—
2026-02-13	Reese Edmund	Tax withheld	251	$321.70
2026-02-12	Simon Mindy F.	Grant	5.5K	—
2026-02-12	Simon Mindy F.	Tax withheld	2.4K	$314.49
2026-02-12	Zeidel Darren	Grant	7.1K	—
2026-02-12	Marcell Andy	Tax withheld	6.6K	$314.49
2026-02-12	Goltermann Lori	Grant	6.9K	—
2026-02-12	Goltermann Lori	Tax withheld	2.7K	$314.49
2026-02-12	Corona Anne	Grant	3.2K	—
2026-02-12	Corona Anne	Tax withheld	1.4K	$314.49
2026-02-12	Case Gregory C	Grant	72K	—
2026-02-12	Case Gregory C	Tax withheld	32K	$314.49
2026-02-12	Case Gregory C	Grant	4.6K	—
2026-02-12	Case Gregory C	Tax withheld	2.1K	$314.49
2026-02-12	Zeidel Darren	Tax withheld	2.7K	$314.49
2026-02-12	Stevens Lisa	Grant	16K	—
2026-02-12	Stevens Lisa	Tax withheld	7.6K	$314.49
2026-02-12	Marcell Andy	Grant	13K	—
2026-02-10	KNIGHT LESTER B	Buy	4.0K	$319.24
2025-12-05	KNIGHT LESTER B	Gift	7.9K	—
2025-11-21	Goltermann Lori	Option exercise	156	—
2025-11-21	Goltermann Lori	Tax withheld	68	$346.51
2025-11-21	Marcell Andy	Option exercise	86	—
2025-11-21	Corona Anne	Tax withheld	65	$346.51
2025-11-21	Corona Anne	Option exercise	132	—
2025-11-21	Marcell Andy	Tax withheld	42	$346.51
2025-11-14	Simon Mindy F.	Option exercise	2.0K	—
2025-11-14	Simon Mindy F.	Tax withheld	606	$350.13
2025-11-12	SANTONA GLORIA	Gift	18K	—
2025-11-12	SANTONA GLORIA	Gift	18K	—
2025-11-05	Zeidel Darren	Sell	7.6K	$344.42
2025-11-05	Zeidel Darren	Sell	1.2K	$345.17
2025-09-26	Jenkins Jo Ann	Tax withheld	263	$356.08
2025-09-26	Jenkins Jo Ann	Grant	547	—
2025-07-01	Reese Edmund	Option exercise	4.0K	—
2025-07-01	Reese Edmund	Tax withheld	2.2K	$356.93
2025-06-26	STAVRIDIS JAMES G.	Grant	637	—
2025-06-26	STAVRIDIS JAMES G.	Tax withheld	153	$353.55
2025-06-26	KNIGHT LESTER B	Grant	1.3K	—
2025-06-26	Alvarez Jose Antonio	Grant	637	—
2025-06-26	Alvarez Jose Antonio	Tax withheld	306	$353.55
2025-06-26	Spruell Byron	Grant	637	—
2025-06-26	Spruell Byron	Tax withheld	153	$353.55
2025-06-26	SMITH SARAH G	Grant	637	—
2025-06-26	SMITH SARAH G	Tax withheld	153	$353.55
2025-06-26	SANTONA GLORIA	Grant	637	—
2025-06-26	SANTONA GLORIA	Tax withheld	153	$353.55
2025-06-26	NOTEBAERT RICHARD C	Grant	637	—
2025-06-26	NOTEBAERT RICHARD C	Tax withheld	153	$353.55
2025-06-26	Karaboutis Adriana	Grant	637	—
2025-06-26	Karaboutis Adriana	Tax withheld	153	$353.55
2025-06-26	FRANCIS CHERYL A	Grant	637	—
2025-06-26	FRANCIS CHERYL A	Tax withheld	153	$353.55
2025-06-26	CAMPBELL JEFFREY C	Grant	637	—
2025-06-26	CAMPBELL JEFFREY C	Tax withheld	153	$353.55
2025-06-26	Cai Jin-Yong	Grant	637	—
2025-06-26	Cai Jin-Yong	Tax withheld	319	$353.55
2025-05-29	NOTEBAERT RICHARD C	Gift	1.8K	—
2025-03-14	Neller Michael	Option exercise	56	—
2025-03-14	Neller Michael	Tax withheld	25	$398.79
2025-02-21	Stevens Lisa	Gift	26	—
2025-02-18	Case Gregory C	Gift	977	—
2025-02-18	NOTEBAERT RICHARD C	Gift	1.3K	—
2025-02-18	Case Gregory C	Gift	977	—
2025-02-18	Case Gregory C	Gift	977	—
2025-02-18	Case Gregory C	Gift	977	—
2025-02-14	Andersen Eric	Option exercise	2.4K	—
2025-02-14	Andersen Eric	Tax withheld	1.2K	$386.99
2025-02-14	Zeidel Darren	Tax withheld	385	$386.99
2025-02-14	Case Gregory C	Tax withheld	1.0K	$386.99
2025-02-14	Neller Michael	Option exercise	146	—
2025-02-14	Neller Michael	Tax withheld	44	$386.99
2025-02-14	Case Gregory C	Gift	18K	—
2025-02-14	Case Gregory C	Gift	18K	—
2025-02-14	Zeidel Darren	Option exercise	374	—
2025-02-14	Zeidel Darren	Tax withheld	166	$386.99
2025-02-14	Zeidel Darren	Option exercise	870	—
2025-02-14	Case Gregory C	Option exercise	2.4K	—
2025-02-14	Stevens Lisa	Option exercise	498	—
2025-02-14	Stevens Lisa	Tax withheld	252	$386.99
2025-02-14	Stevens Lisa	Option exercise	1.4K	—
2025-02-14	Stevens Lisa	Tax withheld	735	$386.99
2025-02-14	Case Gregory C	Gift	18K	—
2025-02-14	Case Gregory C	Gift	18K	—
2025-02-14	Andersen Eric	Option exercise	779	—
2025-02-14	Andersen Eric	Tax withheld	379	$386.99
2025-02-13	Case Gregory C	Tax withheld	3.0K	$390.29
2025-02-13	Case Gregory C	Grant	83K	—
2025-02-13	Stevens Lisa	Grant	15K	—
2025-02-13	Stevens Lisa	Tax withheld	7.4K	$390.29
2025-02-13	Andersen Eric	Grant	28K	—
2025-02-13	Andersen Eric	Tax withheld	14K	$390.29
2025-02-13	Neller Michael	Grant	2.3K	—
2025-02-13	Neller Michael	Tax withheld	688	$390.29
2025-02-13	Zeidel Darren	Grant	8.2K	—
2025-02-13	Zeidel Darren	Tax withheld	3.3K	$390.29
2025-02-13	Case Gregory C	Tax withheld	38K	$390.29
2025-02-13	Case Gregory C	Grant	6.6K	—

All non-derivative Form 4 activity (SEC), newest first.

Supply chain

Customers (1)

RENAISSANCERE HOLDINGS LTD

Suppliers (0)

Named in the 10-K; linked when we track them.

Notable events (8-K)

Date	Items
2026-05-01	ResultsExhibits	filing ↗
2026-01-30	ResultsExhibits	filing ↗
2026-01-07	Exec/director changeExhibits	filing ↗
2026-01-02	Exec/director changeExhibits	filing ↗
2025-10-31	ResultsExhibits	filing ↗
2025-10-30	Reg FD	filing ↗
2025-09-03	Reg FDExhibits	filing ↗
2025-08-04	Exec/director change	filing ↗

Recent filings

Form	Filed	Period	Accession
10-Q	2026-05-01	2026-03-31	0001628280-26-029322 ↗
8-K	2026-05-01	2026-05-01	0001628280-26-029093 ↗
10-K	2026-02-13	2025-12-31	0001628280-26-008116 ↗
8-K	2026-01-30	2026-01-30	0001628280-26-004273 ↗
8-K	2026-01-07	2026-01-06	0001193125-26-005392 ↗
8-K	2026-01-02	2025-12-31	0001193125-26-000263 ↗
10-Q	2025-10-31	2025-09-30	0001628280-25-047805 ↗
8-K	2025-10-31	2025-10-31	0001628280-25-047660 ↗
8-K	2025-10-30	2025-10-30	0001193125-25-258573 ↗
8-K	2025-09-03	2025-09-03	0001193125-25-194474 ↗
8-K	2025-08-04	2025-08-01	0001193125-25-172652 ↗
8-K	2025-07-29	2025-07-29	0001193125-25-168037 ↗