bluebird bio, Inc. (BLUE)
BLUE moved a median of -0.01% 30 minutes after news, and -0.82% by the close. How BLUE actually reacts to news — the realized, point-in-time move the market made, measured across 787 labeled events over the last three years with zero look-ahead.
BLUE’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | -0.14% | 40% | 752 |
| 30-min | -0.01% | 46% | 753 |
| 60-min | -0.43% | 39% | 754 |
| to close | -0.82% | 35% | 754 |
| Middle 50% of BLUE reactions | -1.67% to +1.07% |
|---|---|
| Median reaction (30-min) | -0.01% |
| Measured reactions | 787 |
Half of all bluebird bio, Inc. news events land between -1.67% and +1.07% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How BLUE reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst downgrades | 11 | -9.08% | 9% | -12.23% |
| Coverage initiations | 25 | -0.69% | 40% | -0.20% |
| Rating reiterations | 28 | -0.42% | 39% | -1.81% |
| Price-target cuts | 13 | +0.56% | 62% | -0.42% |
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. 2 further classes were observed with fewer than 10 measured events and are not published. See how BLUE ranks against every other measured name →
That’s how BLUE usually reacts — get an email when it moves on news →Email me when BLUE moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to BLUE's baseline. Nothing else.
Recent BLUE events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Form 15-12G bluebird bio, Inc. | SEC filing · Form 15-12G | SEC EDGAR | — | — | |
| Form EFFECT bluebird bio, Inc. | SEC filing · Form EFFECT | SEC EDGAR | — | — | |
| bluebird bio Announces Completion of Acquisition by Carlyle and SK Capital | Press release | Business Wire | — | — | |
| Form 8-K bluebird bio, Inc. For: Jun 02 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form POS AM bluebird bio, Inc. | SEC filing · Form POS | SEC EDGAR | — | — | |
| Form S-8 POS bluebird bio, Inc. | SEC filing · Form S-8 | SEC EDGAR | — | — | |
| Carlyle and SK Capital Partners Announce Expiration of bluebird bio Tender Offer | Press release | Business Wire | +2.11% | +4.85% | |
| bluebird bio Reminds Stockholders to Act Now to Tender Shares for Acquisition by Carlyle and SK Capital | Press release | Business Wire | +0.00% | +0.20% | |
| Carlyle, SK Capital Partners and bluebird bio Provide Updated Tender Instructions | Press release | Business Wire | +0.20% | +0.20% | |
| Carlyle, SK Capital Partners and bluebird bio Amend Merger Agreement | Press release | Business Wire | -0.20% | +0.20% | |
| Form 10-Q bluebird bio, Inc. For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | +0.00% | -0.20% | |
| Form 8-K bluebird bio, Inc. For: May 13 | SEC filing · Form 8-K | SEC EDGAR | -0.20% | +0.20% | |
| Important Information for bluebird bio Stockholders to Tender Shares for Acquisition by Carlyle and SK Capital | Press release | Business Wire | +0.27% | -6.17% | |
| Carlyle and SK Capital Receive All Required Regulatory Approvals to Complete the Acquisition of bluebird bio | Press release | Business Wire | -2.00% | -2.29% | |
| bluebird bio confirms that Ayrmid, Ltd. has not delivered a binding offer or obtained necessary financing despite extensive engagement | Press release | Business Wire | +0.99% | +3.23% | |
| bluebird bio Confirms Receipt of an Unsolicited Non-Binding Proposal from Ayrmid | Press release | Business Wire | +2.27% | +10.66% | |
| Form 8-K bluebird bio, Inc. For: Mar 28 | SEC filing · Form 8-K | SEC EDGAR | +2.27% | +10.66% | |
| Form 10-K bluebird bio, Inc. For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | -0.93% | +7.94% | |
| Blue Stock Alert: Halper Sadeh LLC Is Investigating Whether the Sale of Bluebird Bio, Inc. is Fair to Shareholders | Press release | ACCESS Newswire | +0.00% | +3.63% | |
| ALERT: Rowley Law PLLC is Investigating Proposed Acquisition of bluebird bio, Inc. | Press release | PR Newswire | +0.00% | +0.25% | |
| BLUE Stock Alert: Halper Sadeh LLC Is Investigating Whether the Sale of bluebird bio, Inc. Is Fair to Shareholders | Press release | Business Wire | -5.10% | -16.73% | |
| bluebird bio Announces Definitive Agreement to be Acquired by Carlyle and SK Capital | Press release | Business Wire | -5.10% | -16.73% | |
| Form 8-K bluebird bio, Inc. For: Feb 21 | SEC filing · Form 8-K | SEC EDGAR | -5.10% | -16.73% | |
| Form 8-K bluebird bio, Inc. For: Feb 13 | SEC filing · Form 8-K | SEC EDGAR | -5.10% | -16.73% | |
| Form 8-K bluebird bio, Inc. For: Dec 12 | SEC filing · Form 8-K | SEC EDGAR | -4.63% | +24.76% | |
| bluebird bio Presents Positive Long-Term Data On LYFGENIA™ (lovotobegligene autotemcel) Gene Therapy for Sickle Cell Disease at 66th American Society of Hematology (ASH) Annual Meeting and Exposition | Press release | Business Wire | -6.82% | -11.96% | |
| Long-Term Follow-Up Data Continue to Support Beti-Cel as a Potentially Curative Gene Therapy for ß-Thalassemia Patients Who Require Regular Transfusions Through Achievement of Durable Transfusion Independence and Normal or Near-Normal Adult Hb Levels | Press release | Business Wire | -6.82% | -11.96% | |
| bluebird bio Announces 1-for-20 Reverse Stock Split | Press release | Business Wire | +6.77% | -10.02% | |
| bluebird bio Confirms Participation in Center for Medicare and Medicaid Innovation (CMMI) Cell and Gene Therapy Access Model | Press release | Business Wire | +1.39% | +104.53% | |
| Form 8-K bluebird bio, Inc. For: Dec 04 | SEC filing · Form 8-K | SEC EDGAR | +6.77% | -10.02% | |
| bluebird bio Reports Third Quarter 2024 Results and Highlights Operational Progress and 2024 Guidance | Press release | Business Wire | -0.32% | -2.26% | |
| Form 10-Q bluebird bio, Inc. For: Sep 30 | SEC filing · Form 10-Q | SEC EDGAR | -0.32% | -2.26% | |
| Form 8-K bluebird bio, Inc. For: Nov 14 | SEC filing · Form 8-K | SEC EDGAR | -0.32% | -2.26% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | -6.46% | -12.23% | |
| Form S-8 bluebird bio, Inc. | SEC filing · Form S-8 | SEC EDGAR | -6.46% | -12.23% | |
| bluebird bio Adjourns Meeting of Stockholders and Announces Third Quarter Results Call | Press release | Business Wire | -8.02% | -11.14% | |
| Form 8-K bluebird bio, Inc. For: Nov 06 | SEC filing · Form 8-K | SEC EDGAR | -8.02% | -11.14% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | -8.02% | -11.14% | |
| bluebird bio to Present Additional Long-Term Follow-up Data from Gene Therapy Programs in Sickle Cell Disease and Beta-Thalassemia at the 66th American Society of Hematology (ASH) Annual Meeting and Exposition | Press release | Business Wire | +0.63% | -1.65% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | +1.06% | +0.65% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | -1.20% | -3.79% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | -0.98% | -3.76% | |
| bluebird bio Reports Inducement Grants Under Nasdaq Listing Rule 5635(c)(4) | Press release | Business Wire | +0.65% | -5.64% | |
| Form 8-K bluebird bio, Inc. For: Sep 30 | SEC filing · Form 8-K | SEC EDGAR | +0.65% | -5.64% | |
| bluebird bio Announces Completion of its Q2 2024 Form 10-Q Filing | Press release | Business Wire | +1.90% | -0.10% | |
| Form 10-Q bluebird bio, Inc. For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | +1.90% | -0.10% | |
| Form ARS bluebird bio, Inc. For: Dec 31 | SEC filing · Form ARS | SEC EDGAR | +0.86% | +0.84% | |
| Form DEF 14A bluebird bio, Inc. For: Nov 06 | SEC filing · Form DEF | SEC EDGAR | +0.86% | +0.84% | |
| Form DEFA14A bluebird bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | +0.86% | +0.84% | |
| bluebird bio Initiates Restructuring Intended to Optimize Cost Structure and Enable Quarterly Cash Flow Break-Even in the Second Half of 2025 | Press release | Business Wire | -0.87% | -1.44% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the BLUE section they belong to.
Where else BLUE is measured.
BLUE earnings → · Analyst actions → · SEC filings →
Other Healthcare names, measured the same way
| Ticker | Events | Median 30-min | % positive |
|---|---|---|---|
| Cerecor, Inc (CERC) | 795 | -0.03% | 43% |
| Second Sight Medical Products, Inc. (EYES) | 788 | -0.56% | 34% |
| Actinium Pharmaceuticals, Inc. (Delaware) (ATNM) | 784 | 0.00% | 45% |
| Heat Biologics, Inc. (HTBX) | 781 | -0.40% | 41% |
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 Healthcare names, measured the same way →
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Every name we’ve measured, in one place.
How the numbers are made.
How is bluebird bio, Inc.'s median reaction calculated?
Every labeled BLUE 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 787 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. 46% of BLUE'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 BLUE'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.