AON vs MRSH
Aon plc (AON) and Marsh & Mclennan Companies, Inc. (MRSH) are both filed with the SEC under Insurance Agents, Brokers & Service. MRSH is 1.2× AON's size by market cap ($90.7B against $74.2B); MRSH trades at the higher fiscal-year P/E (22.5× against 20.5×); AON reports the higher net margin (21.5% against 15.4%); AON grew sales faster over three years (+11.2% against +9.2%); and over the past year AON returned -2.1% against MRSH's -6.0%.
| AON | MRSH | |
|---|---|---|
| Last close | $355.40 | $190.00 |
| Market cap | $74.2B | $90.7B |
| P/E (FY) | 20.5× | 22.5× |
| P/S | 4.3× | 3.4× |
| EV/EBITDA | — | 16.3× |
| Operating margin | 25.3% | 23.1% |
| Net margin | 21.5% | 15.4% |
| Return on equity | 47.8% | — |
| Sales growth (3y) | +11.2% | +9.2% |
| EPS growth (3y) | +11.9% | +11.8% |
| Dividend yield | 0.8% | 1.9% |
| 1-year return | -2.1% | -6.0% |
Screener snapshot — prices as of 2026-08-28. Each side's last close is the most recent session the snapshot holds for that company, which can be an earlier one, and its 1-year return is measured to that close. Market caps struck on 2026-08-27. Last close, market cap and the 1-year return are price figures; every other row is computed over the company's latest filed fiscal year — FY2025 (ended 2025-12-31) for both. — not published for this company. A ratio goes unpublished for more than one reason: a component the calculation needs is not on file, the filing does not tag the line it is read from, or the calculation is not defined on the filed basis — EV/EBITDA is not printed on non-positive EBITDA, and return on equity is not computed on a zero or negative equity base.
Who holds them, and who has traded them
| AON | MRSH | |
|---|---|---|
| Institutional holders (13F) | 1,247 | 1,522 |
| Insider buyers − sellers (180d) | — | -3 |
| Congressional trades disclosed (180d) | 1 | 1 |
| Executive-branch officials on file — trades disclosed (180d) | 9 | 9 |
Counts only. The congressional figures count transactions dated in the trailing 180 days and disclosed in STOCK Act periodic transaction reports; amounts are filed as ranges and are never summed. The executive-branch figures count the same window of transactions, and they are scoped to one roster. The officials OGE posts for direct download. Insider buyers − sellers counts distinct people filing open-market Form 4 purchases minus distinct people filing open-market sales over the trailing 180 days, capped at ±5. — no open-market Form 4 purchases or sales in the window.
AON vs MRSH: common questions
- Is AON bigger than MRSH?
- MRSH carries the larger market cap — $90.7B against $74.2B, both struck on 2026-08-27.
- Which trades at a higher P/E, AON or MRSH?
- MRSH, at a fiscal-year 22.5× against 20.5× for AON. Both are price ÷ latest full-year diluted earnings per share, not a trailing-twelve-month P/E.
- How have AON and MRSH performed over the past year?
- AON returned -2.1% and MRSH -6.0%, measured on the trailing calendar year to the last close.
- How many institutions hold AON and MRSH?
- 1,247 13F filers report a position in AON and 1,522 in MRSH, on the latest quarter in the panel.
- Are AON and MRSH in the same industry?
- Both are filed with the SEC under Insurance Agents, Brokers & Service, which is the classification this pairing is built on.
AON overview → · MRSH overview → · AON institutional ownership → · MRSH institutional ownership → · Congress and AON → · Congress and MRSH → · Executive branch and AON → · Executive branch and MRSH →
More in Insurance Agents, Brokers & Service: AON vs WTW · MRSH vs WTW
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Source: SPZCO — https://spzco.com/vs/aon-vs-mrsh