Anthem (now Elevance Health)
Anthem disclosed a sophisticated external attack that obtained personal information associated with tens of millions of people.
+6.5% ANTM vs +3.0% 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 sessionFeb 4, 2015
Normalized to 100 for both ANTM and SPY.
- 02Public disclosureFeb 4, 2015, 10:15 PM EST
Documented publication time.
- 03First reaction closeFeb 5, 2015
-0.3% company total return versus +1.0% for SPY; -1.3 pp market-relative return.
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 | ANTM | SPY | Market-relative | Signal |
|---|---|---|---|---|---|
| First reaction | Feb 5, 2015 | -0.3% | +1.0% | -1.3 pp | Below SPY |
| +7 days | Feb 11, 2015 | +2.8% | +1.4% | +1.4 pp | Above SPY |
| +1 month | Mar 4, 2015 | +6.5% | +3.0% | +3.4 pp | Above SPY |
| +3 months | May 4, 2015 | +13.7% | +4.0% | +9.7 pp | Above SPY |
| +6 months | Aug 4, 2015 | +11.7% | +3.6% | +8.1 pp | Above SPY |
| +12 months | Feb 4, 2016 | -6.4% | -4.2% | -2.2 pp | Below SPY |
Compare with current catalog aggregates
| Window | This case | Catalog median | Catalog mean | n |
|---|---|---|---|---|
| First reaction | -1.3 pp | -0.8 pp | -1.5 pp | 30 |
| +7 days | +1.4 pp | -2.0 pp | -4.0 pp | 30 |
| +1 month | +3.4 pp | -6.6 pp | -6.8 pp | 30 |
| +3 months | +9.7 pp | -5.1 pp | -6.6 pp | 30 |
| +6 months | +8.1 pp | -5.6 pp | -7.5 pp | 30 |
| +12 months | -2.2 pp | -3.7 pp | -10.1 pp | 30 |
Normalized total return
ANTM compared with SPY
Baseline session = 100. Adjusted close reflects splits and reinvested distributions.
Anthem (now Elevance Health) had -6.4% company total return versus -4.2% for SPY; -2.2 pp market-relative return. The chart shows normalized adjusted-close performance for up to 24 months.
View tabular chart fallback
| Date | ANTM | SPY |
|---|---|---|
| Feb 4, 2015 | 100.0 | 100.0 |
| Mar 6, 2015 | 105.9 | 101.7 |
| Apr 7, 2015 | 113.2 | 102.0 |
| May 6, 2015 | 116.6 | 102.4 |
| Jun 5, 2015 | 118.8 | 103.3 |
| Jul 7, 2015 | 117.4 | 102.9 |
| Aug 5, 2015 | 113.5 | 103.9 |
| Sep 3, 2015 | 104.7 | 96.7 |
| Oct 5, 2015 | 105.1 | 98.7 |
| Nov 3, 2015 | 100.8 | 104.9 |
| Dec 3, 2015 | 95.7 | 102.2 |
| Jan 5, 2016 | 104.4 | 100.7 |
| Feb 4, 2016 | 93.6 | 95.8 |
| Mar 7, 2016 | 98.4 | 100.3 |
| Apr 6, 2016 | 107.6 | 103.8 |
| May 5, 2016 | 101.8 | 103.0 |
| Jun 6, 2016 | 98.4 | 106.3 |
| Jul 6, 2016 | 98.6 | 106.0 |
| Aug 4, 2016 | 94.6 | 109.4 |
| Sep 2, 2016 | 92.7 | 110.4 |
| Oct 4, 2016 | 91.9 | 109.0 |
| Nov 2, 2016 | 92.3 | 106.5 |
| Dec 2, 2016 | 109.4 | 111.6 |
| Jan 4, 2017 | 107.8 | 115.8 |
| Feb 3, 2017 | 119.9 | 117.2 |
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
- -2.0% on Feb 9, 2015
- Recovery close
- Feb 10, 2015
- Calendar days
- 6
- Observation cap
- 24 months after disclosure
Hypothetical $1,000
What would $1,000 have looked like?
Compare $1,000 in ANTM with $1,000 in SPY, bought and measured on the same dates.
Entry Feb 9, 2015 Exit Aug 7, 2015
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
Anthem reported that attackers had gained unauthorized access to systems holding names, birth dates, health-care identifiers, Social Security numbers, addresses and employment information. The insurer undertook notification and identity-protection measures.
The earliest traceable timestamp in the cited contemporaneous reporting is 10:15 p.m. ET, after the February 4 close. The February 4 adjusted close is therefore the baseline and February 5 is the first reaction session; ELV is used as Yahoo’s continuous successor symbol.
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 Feb 19, 2016Anthem 2015 Form 10-K — Cyber Attack Incident Anthem / U.S. SEC Supports: Disclosure, Listing, Impact, Description
- secondary Feb 4, 2015Health insurer Anthem hit by massive cybersecurity breach Reuters, syndicated by Fortune Supports: Disclosure, Timing, Impact
- Listing evidenceChecked Jul 20, 2026Anthem 2015 Form 10-K U.S. Securities and Exchange Commission SEC issuer history and event-period reporting confirm Anthem's NYSE listing under ANTM at disclosure.
Why it is included. The attack directly affected the health insurer, exposed highly sensitive identity information at exceptional scale and triggered extensive notification, litigation and regulatory response. Reviewed Jul 20, 2026.