Marriott International
Marriott disclosed long-running unauthorized access to the legacy Starwood reservation database, affecting hundreds of millions of guest records.
-12.0% MAR vs -9.0% 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 sessionNov 29, 2018
Normalized to 100 for both MAR and SPY.
- 02Public disclosureNov 30, 2018 · time unknown
Publication time is not documented; lower timing precision.
- 03First reaction closeNov 30, 2018
-5.6% company total return versus +0.6% for SPY; -6.2 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 | MAR | SPY | Market-relative | Signal |
|---|---|---|---|---|---|
| First reaction | Nov 30, 2018 | -5.6% | +0.6% | -6.2 pp | Below SPY |
| +7 days | Dec 7, 2018 | -8.7% | -3.8% | -4.9 pp | Below SPY |
| +1 month | Dec 28, 2018 | -12.0% | -9.0% | -2.9 pp | Below SPY |
| +3 months | Feb 28, 2019 | +3.1% | +2.3% | +0.8 pp | Above SPY |
| +6 months | May 30, 2019 | +3.0% | +2.9% | +0.1 pp | Above SPY |
| +12 months | Nov 29, 2019 | +16.9% | +17.0% | -0.1 pp | Below SPY |
Compare with current catalog aggregates
| Window | This case | Catalog median | Catalog mean | n |
|---|---|---|---|---|
| First reaction | -6.2 pp | -0.8 pp | -1.5 pp | 30 |
| +7 days | -4.9 pp | -2.0 pp | -4.0 pp | 30 |
| +1 month | -2.9 pp | -6.6 pp | -6.8 pp | 30 |
| +3 months | +0.8 pp | -5.1 pp | -6.6 pp | 30 |
| +6 months | +0.1 pp | -5.6 pp | -7.5 pp | 30 |
| +12 months | -0.1 pp | -3.7 pp | -10.1 pp | 30 |
Normalized total return
MAR compared with SPY
Baseline session = 100. Adjusted close reflects splits and reinvested distributions.
Marriott International had +16.9% company total return versus +17.0% for SPY; -0.1 pp market-relative return. The chart shows normalized adjusted-close performance for up to 24 months.
View tabular chart fallback
| Date | MAR | SPY |
|---|---|---|
| Nov 29, 2018 | 100.0 | 100.0 |
| Jan 2, 2019 | 88.2 | 91.8 |
| Feb 1, 2019 | 94.0 | 99.1 |
| Mar 5, 2019 | 103.1 | 102.4 |
| Apr 3, 2019 | 108.4 | 105.6 |
| May 3, 2019 | 115.4 | 108.4 |
| Jun 4, 2019 | 105.9 | 103.4 |
| Jul 3, 2019 | 117.2 | 110.7 |
| Aug 2, 2019 | 112.4 | 108.4 |
| Sep 3, 2019 | 103.1 | 107.7 |
| Oct 2, 2019 | 99.8 | 107.2 |
| Oct 31, 2019 | 105.0 | 112.9 |
| Dec 2, 2019 | 116.9 | 116.0 |
| Jan 2, 2020 | 126.1 | 121.5 |
| Feb 3, 2020 | 117.8 | 121.2 |
| Mar 4, 2020 | 98.9 | 117.0 |
| Apr 2, 2020 | 52.7 | 94.8 |
| May 4, 2020 | 69.0 | 106.7 |
| Jun 3, 2020 | 83.5 | 117.5 |
| Jul 2, 2020 | 73.4 | 118.0 |
| Aug 3, 2020 | 69.8 | 124.3 |
| Sep 1, 2020 | 86.2 | 133.3 |
| Oct 1, 2020 | 78.9 | 127.9 |
| Oct 30, 2020 | 77.6 | 123.9 |
| Nov 30, 2020 | 106.0 | 137.4 |
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
- -8.7% on Dec 7, 2018
- Recovery close
- Feb 19, 2019
- Calendar days
- 81
- Observation cap
- 24 months after disclosure
Hypothetical $1,000
What would $1,000 have looked like?
Compare $1,000 in MAR with $1,000 in SPY, bought and measured on the same dates.
Entry Dec 3, 2018 Exit Jun 3, 2019
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
Marriott announced that an unauthorized party had accessed and copied information from the legacy Starwood reservation environment. The affected data included guest identity, contact, travel and, in some cases, passport and payment-card information.
The case is assigned to the listed parent because Marriott owned and operated the affected business at disclosure. The source gives a date but no retained publication time, so November 29 is the baseline session.
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 30, 2018Marriott announces Starwood guest reservation database security incident Marriott International / U.S. SEC Supports: Disclosure, Impact, Description
- primary Nov 30, 2018Marriott November 30, 2018 Form 8-K Marriott International / U.S. SEC Supports: Listing, Impact
- Listing evidenceChecked Jul 20, 2026Marriott November 30, 2018 Form 8-K U.S. Securities and Exchange Commission The event-period filing identifies Marriott as the Nasdaq-listed parent issuing the disclosure.
Why it is included. Marriott directly controlled the affected Starwood systems, publicly documented the disclosure date and reported a global guest-record exposure large enough to trigger extensive regulatory action. Reviewed Jul 20, 2026.