Merck & Co.
NotPetya disrupted Merck's worldwide manufacturing, research and sales operations and produced hundreds of millions of dollars in recorded effects.
-3.4% MRK vs +1.6% SPY
This site shows how share prices moved after an incident became public. It does not prove that the incident caused the move. Company news, sector moves and the wider market can affect every result. Educational only — not investment advice.
Disclosure timing
When could the market react?
The baseline is the last adjusted close before the news was public. The reaction session is the first close afterward.
- 01Baseline sessionJun 26, 2017
Normalized to 100 for both MRK and SPY.
- 02Public disclosureJun 27, 2017 · time unknown
Publication time is not documented; lower timing precision.
- 03First reaction closeJun 27, 2017
-0.6% company total return versus -0.8% for SPY; +0.2 pp market-relative return.
Disclosure time is unknown; the previous session close is used as baseline.
Time windows
Company vs SPY
Each row uses the last trading session on or before its target date. “Market-relative” is the company return minus the SPY return, in percentage points.
| Window | Endpoint | MRK | SPY | Market-relative | Signal |
|---|---|---|---|---|---|
| First reaction | Jun 27, 2017 | -0.6% | -0.8% | +0.2 pp | Above SPY |
| +7 days | Jul 3, 2017 | -2.5% | -0.4% | -2.1 pp | Below SPY |
| +1 month | Jul 27, 2017 | -3.4% | +1.6% | -5.0 pp | Below SPY |
| +3 months | Sep 27, 2017 | -1.3% | +3.3% | -4.6 pp | Below SPY |
| +6 months | Dec 27, 2017 | -13.2% | +11.0% | -24.2 pp | Below SPY |
| +12 months | Jun 27, 2018 | -6.2% | +12.8% | -19.0 pp | Below SPY |
Compare with current catalog aggregates
| Window | This case | Catalog median | Catalog mean | n |
|---|---|---|---|---|
| First reaction | +0.2 pp | -0.8 pp | -1.5 pp | 30 |
| +7 days | -2.1 pp | -2.0 pp | -4.0 pp | 30 |
| +1 month | -5.0 pp | -6.6 pp | -6.8 pp | 30 |
| +3 months | -4.6 pp | -5.1 pp | -6.6 pp | 30 |
| +6 months | -24.2 pp | -5.6 pp | -7.5 pp | 30 |
| +12 months | -19.0 pp | -3.7 pp | -10.1 pp | 30 |
Normalized total return
MRK compared with SPY
Baseline session = 100. Adjusted close reflects splits and reinvested distributions.
Merck & Co. had -6.2% company total return versus +12.8% for SPY; -19.0 pp market-relative return. The chart shows normalized adjusted-close performance for up to 24 months.
View tabular chart fallback
| Date | MRK | SPY |
|---|---|---|
| Jun 26, 2017 | 100.0 | 100.0 |
| Jul 26, 2017 | 93.8 | 101.7 |
| Aug 24, 2017 | 95.1 | 100.3 |
| Sep 25, 2017 | 99.6 | 102.8 |
| Oct 24, 2017 | 96.4 | 106.0 |
| Nov 22, 2017 | 83.1 | 107.3 |
| Dec 22, 2017 | 86.8 | 111.1 |
| Jan 25, 2018 | 94.5 | 117.6 |
| Feb 26, 2018 | 86.4 | 115.4 |
| Mar 27, 2018 | 83.6 | 108.6 |
| Apr 26, 2018 | 92.3 | 111.0 |
| May 25, 2018 | 91.9 | 113.4 |
| Jun 26, 2018 | 95.1 | 113.7 |
| Jul 26, 2018 | 100.3 | 118.6 |
| Aug 24, 2018 | 108.1 | 120.4 |
| Sep 25, 2018 | 111.4 | 122.3 |
| Oct 24, 2018 | 111.3 | 111.6 |
| Nov 23, 2018 | 117.8 | 110.7 |
| Dec 26, 2018 | 117.5 | 104.2 |
| Jan 28, 2019 | 115.8 | 111.6 |
| Feb 27, 2019 | 128.0 | 118.1 |
| Mar 28, 2019 | 132.1 | 119.3 |
| Apr 29, 2019 | 122.8 | 124.9 |
| May 29, 2019 | 126.9 | 118.2 |
| Jun 27, 2019 | 134.9 | 124.5 |
Price recovery
Recovered
Here, recovery only means that adjusted close reached the baseline again. It does not mean every effect of the incident ended.
- State
- Recovered
- Initial trough
- -2.8% on Jun 30, 2017
- Recovery close
- Sep 14, 2017
- Calendar days
- 79
- Observation cap
- 24 months after disclosure
Hypothetical $1,000
What would $1,000 have looked like?
Compare $1,000 in MRK with $1,000 in SPY, bought and measured on the same dates.
Entry Jun 30, 2017 Exit Dec 29, 2017
Uses fractional shares and adjusted close. Leaves out taxes, fees and slippage. The holding period starts on the purchase date. This is a historical illustration, not an investment strategy.
Case note
Merck reported that the June 27 NotPetya attack disrupted worldwide operations, including manufacturing, research and sales. It later quantified lost sales, manufacturing variances and remediation expenses and described supply constraints for some products.
This is one company-event observation within the shared notpetya-2017 cluster. Merck’s return remains separate from other victims, preventing a single campaign from being treated as one issuer-level outcome.
Shared campaign
Other Notpetya 2017 cases
The cases share a campaign, but each company keeps its own returns.
Evidence
Sources and case review
We qualify each case before checking its price results. These links support the disclosure date, listing, incident and business impact.
- primary Nov 3, 2017Merck third-quarter 2017 Form 10-Q — Cyber-attack Merck & Co. / U.S. SEC Supports: Disclosure, Listing, Impact, Description
- Listing evidenceChecked Jul 20, 2026Merck third-quarter 2017 Form 10-Q U.S. Securities and Exchange Commission The event-period filing identifies Merck as the listed issuer and documents the June 27 attack.
Why it is included. Merck was a direct NotPetya victim and later quantified disruption to manufacturing, research, sales, revenue and remediation, satisfying both operational and financial materiality signals. Reviewed Jul 20, 2026.