Marsh & McLennan Companies, Inc. (MMC)
MMC moved a median of +0.01% 30 minutes after news, and -0.03% by the close. How MMC actually reacts to news — the realized, point-in-time move the market made, measured across 550 labeled events over the last three years with zero look-ahead.
MMC’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | -0.04% | 44% | 416 |
| 30-min | +0.01% | 51% | 416 |
| 60-min | +0.01% | 51% | 416 |
| to close | -0.03% | 47% | 408 |
| Middle 50% of MMC reactions | -0.37% to +0.26% |
|---|---|
| Median reaction (30-min) | +0.01% |
| Measured reactions | 550 |
Half of all Marsh & McLennan Companies, Inc. news events land between -0.37% and +0.26% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How MMC reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst upgrades | 17 | +0.01% | 65% | +0.01% |
| Analyst downgrades | 16 | +0.12% | 56% | +0.54% |
| Coverage initiations | 23 | +0.08% | 52% | +0.21% |
| Rating reiterations | 67 | -0.03% | 42% | +0.07% |
| Price-target raises | 40 | -0.06% | 40% | -0.12% |
| Price-target cuts | 21 | +0.04% | 57% | +0.03% |
Last 3 years, pulled 2026-09-21. Reaction = percent move vs. the price at the news timestamp. Counts and medians only. The same measurement runs across every name in the dataset. See how MMC ranks against every other measured name →
That’s how MMC usually reacts — get an email when it moves on news →Email me when MMC moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to MMC's baseline. Nothing else.
Recent MMC events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Marsh Appoints Birgit Boykin Chief People Officer of Oliver Wyman and Marsh Management Consulting | Press release | Business Wire | — | — | |
| Marsh's Oliver Wyman joins Anthropic's Claude Partner Network | Press release | Business Wire | — | — | |
| Marsh McLennan Agency to Acquire Accel Holdings, Inc. | Press release | Business Wire | — | — | |
| Form 10-Q MARSH & MCLENNAN COMPANI For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Jul 21 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| AI is Creating a New Competitive Divide Across Transport, Logistics and Defense, New Report From Oliver Wyman Forum Finds | Press release | Business Wire | — | — | |
| Form 11-K MARSH & MCLENNAN COMPANI For: Dec 31 | SEC filing · Form 11-K | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Jun 02 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Andrew Bainbridge named General Counsel & Chief Compliance Officer of Oliver Wyman and Marsh Management Consulting | Press release | Business Wire | — | — | |
| Marsh McLennan Agency completes acquisition of TriBridge Partners | Press release | Business Wire | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: May 21 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Emerging Urban Hubs Reshaping Global Investment, Manufacturing, and Talent Flows, New Report From Oliver Wyman Finds | Press release | Business Wire | — | — | |
| Marsh’s Oliver Wyman announces senior leadership appointments to accelerate AI-enabled integration and transformation | Press release | Business Wire | — | — | |
| Marsh’s Oliver Wyman to Acquire Management Consulting Firm CR3 Partners | Press release | Business Wire | — | — | |
| Marsh McLennan Agency to Acquire TriBridge Partners | Press release | Business Wire | — | — | |
| Form 10-Q MARSH & MCLENNAN COMPANI For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Apr 16 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Apr 08 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| CEOs Convert Disruption Into Competitive Advantage, Oliver Wyman Forum and New York Stock Exchange Survey Finds | Press release | Business Wire | — | — | |
| Marsh McLennan Agency Acquires Seitz Insurance Agency | Press release | Business Wire | — | — | |
| Form ARS MARSH & MCLENNAN COMPANI For: Dec 31 | SEC filing · Form ARS | SEC EDGAR | — | — | |
| Form DEF 14A MARSH & MCLENNAN COMPANI For: May 21 | SEC filing · Form DEF | SEC EDGAR | — | — | |
| Form DEFA14A MARSH & MCLENNAN COMPANI | SEC filing · Form DEFA14A | SEC EDGAR | — | — | |
| Oliver Wyman appoints Helen Leis as Global Head of Leadership and Change | Press release | Business Wire | — | — | |
| Emerging Technology Could Help Manage Healthcare Costs as Spending Poised to Reach $23 Trillion by 2040, Oliver Wyman Analysis Shows | Press release | Business Wire | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Mar 10 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Feb 25 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Feb 19 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form S-8 MARSH & MCLENNAN COMPANI | SEC filing · Form S-8 | SEC EDGAR | — | — | |
| Form 10-K MARSH & MCLENNAN COMPANI For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | — | — | |
| Marsh McLennan Agency Acquires Robinson & Son | Press release | Business Wire | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Jan 29 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Marsh McLennan Agency Launches Secure Harbor Group Captive to Help Senior Living Clients Manage Challenging Market Conditions | Press release | Business Wire | — | — | |
| Deep Shifts in Human Sentiment Are Redefining Economic, Health, and Workplace Norms, Oliver Wyman Forum Report Finds | Press release | Business Wire | — | — | |
| Sports Economy Set to Reach $8.8 Trillion by 2050, But Physical Inactivity and Climate Threats Risk Billions Without Urgent Action | Press release | Business Wire | — | — | |
| Form 8-K MARSH & MCLENNAN COMPANI For: Jan 14 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Marsh McLennan to Change Its NYSE Symbol to “MRSH” on January 14; Hosts Fourth Quarter Earnings Investor Call on January 29 | Press release | Business Wire | +0.04% | -0.13% | |
| Marsh McLennan appoints Mike Mathews Digital Infrastructure Leader | Press release | Business Wire | +0.07% | -0.01% | |
| Mercer China Unveils the Recipients of Its 2025 Star Employers Awards | Press release | Business Wire | +0.20% | -0.28% | |
| Mercer Reveals Average Salary in Thailand Set to Increase by 5.2% in 2026 | Press release | Business Wire | +0.20% | -0.28% | |
| Marsh McLennan’s Mercer to Invest in a Bespoke Long-Term Asset Fund for Private Markets With an Initial Commitment of £350 Million | Press release | Business Wire | -0.01% | +0.51% | |
| Most US Employers Plan to Keep 2026 Salary Increases Flat to 2025, According to Mercer | Press release | Business Wire | +0.21% | -0.38% | |
| Rising Third-Party Risks and Persistent Ransomware Threats Drive Increased Cybersecurity Investments in 2026: Marsh Report | Press release | Business Wire | +0.07% | -0.34% | |
| New report from Oliver Wyman and Association of Equipment Manufacturers finds rising uncertainty is reshaping equipment manufacturing | Press release | Business Wire | +0.02% | +0.05% | |
| Marsh McLennan Agency Acquires Three Hawai‘i-based Insurance Brokerages | Press release | Business Wire | +0.02% | -0.33% | |
| Marsh McLennan Authorizes Renewal of Share Repurchase Program | Press release | Business Wire | +0.06% | +0.26% | |
| Oliver Wyman Announces Newly Elected Partners and Executive Directors for 2026 | Press release | Business Wire | -0.07% | +0.78% | |
| Mercer Survey Finds US Employers and Workers Will Face Affordability Crunch as Health Insurance Cost Is Expected to Exceed $18,500 Per Employee in 2026 | Press release | Business Wire | -0.08% | -0.50% | |
| Mercer’s Research Shows US Defined Contribution (DC) Plan Sponsors Are Prioritizing Financial Wellness, AI Integration and Delegation in 2026 | Press release | Business Wire | +0.23% | +0.79% | |
| Leadership Vacuum Fuels Tech Anxiety in the Workplace, According to Mercer | Press release | Business Wire | +0.13% | -1.40% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the MMC section they belong to.
Where else MMC is measured.
MMC earnings → · Analyst actions → · SEC filings →
Other Financial Services names, measured the same way
| Ticker | Events | Median 30-min | % positive |
|---|---|---|---|
| NexPoint Strategic Opportunities Fund (NHF) | 558 | 0.00% | 44% |
| Peoples Bancorp Inc. (PEBO) | 558 | -0.07% | 43% |
| National Security Group, Inc. (NSEC) | 546 | 0.00% | 29% |
| Voya Financial, Inc. (VOYA) | 545 | +0.06% | 52% |
Same sector, same measurement: percent move vs. the price at the news timestamp, read at 30 minutes. Sample sizes differ, so the medians are comparable but the confidence behind them is not.
All Financial Services names, measured the same way →
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How the numbers are made.
How is Marsh & McLennan Companies, Inc.'s median reaction calculated?
Every labeled MMC news event is measured from its own timestamp: the last trade before the news is the base price, and the move is read at fixed horizons — 30 minutes of trading, then the close. The median across 550 events is what this page reports. Point-in-time, zero look-ahead: no event borrows information from a later one.
What counts as a positive reaction?
Any event whose price move is above zero at the horizon, relative to the last trade before the news timestamp. 51% of MMC's measured events are up at 30 minutes; the rest close the window flat or negative.
How often is this page updated?
The news table refreshes automatically as new events are labeled and priced. The reaction medians are re-pulled in batches from the dataset — the figures here are as of 2026-09-21.
Does MMC's past reaction predict its next one?
No. These are realized facts about past events, not forecasts. They describe a distribution — they say nothing certain about any future move.