Gritstone bio, Inc. (GRTS)
GRTS moved a median of -0.01% 30 minutes after news, and -0.45% by the close. How GRTS actually reacts to news — the realized, point-in-time move the market made, measured across 659 labeled events over the last three years with zero look-ahead.
GRTS’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | +0.15% | 57% | 653 |
| 30-min | -0.01% | 50% | 653 |
| 60-min | -0.11% | 44% | 653 |
| to close | -0.45% | 41% | 655 |
| Middle 50% of GRTS reactions | -1.40% to +1.26% |
|---|---|
| Median reaction (30-min) | -0.01% |
| Measured reactions | 659 |
Half of all Gritstone bio, Inc. news events land between -1.40% and +1.26% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How GRTS reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst downgrades | 10 | -10.54% | 0% | -10.33% |
| Rating reiterations | 17 | -0.51% | 47% | +0.96% |
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. 4 further classes were observed with fewer than 10 measured events and are not published. See how GRTS ranks against every other measured name →
That’s how GRTS usually reacts — get an email when it moves on news →Email me when GRTS moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to GRTS's baseline. Nothing else.
Recent GRTS events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Gritstone bio Announces Strengthening of Maturing Phase 2 PFS Data for GRANITE Study and Provides Business Update | Press release | GlobeNewswire | — | — | |
| Form 8-K Gritstone bio, Inc. For: Oct 11 | SEC filing · Form 8-K | SEC EDGAR | +6.20% | +4.00% | |
| Form 8-K Gritstone bio, Inc. For: Oct 10 | SEC filing · Form 8-K | SEC EDGAR | +1.25% | -22.38% | |
| Gritstone bio Takes Action to Preserve Value and Strengthen Capital Structure | Press release | Business Wire | +1.25% | -22.38% | |
| Form 8-K Gritstone bio, Inc. For: Sep 30 | SEC filing · Form 8-K | SEC EDGAR | +0.78% | -51.26% | |
| Gritstone bio Announces Interim Phase 2 Data for GRANITE Individualized Neoantigen Targeting Immunotherapy in Frontline Metastatic Microsatellite Stable Colorectal Cancer | Press release | GlobeNewswire | +0.78% | -51.26% | |
| Form 10-Q Gritstone bio, Inc. For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | -2.33% | -5.46% | |
| Form 8-K Gritstone bio, Inc. For: Aug 13 | SEC filing · Form 8-K | SEC EDGAR | -2.33% | -5.46% | |
| Gritstone bio Reports Second Quarter 2024 Financial Results and Provides Corporate Updates | Press release | GlobeNewswire | -2.33% | -5.46% | |
| Gritstone Bio Inc Sued for Securities Law Violations - Contact the DJS Law Group to Discuss Your Rights - GRTS | Press release | PR Newswire | -3.38% | +1.53% | |
| Gritstone bio to Host Virtual KOL Event to Discuss Unmet Need and Potential Role of Its Personalized Cancer Vaccine, GRANITE, in Metastatic Microsatellite Stable Colorectal Cancer (MSS-CRC) | Press release | GlobeNewswire | +0.27% | -4.53% | |
| Gritstone bio Announces Inducement Grants Under Nasdaq Listing Rule 5635(c)(4) | Press release | GlobeNewswire | +0.85% | -2.88% | |
| Gritstone Bio Inc Sued for Securities Law Violations - Contact the DJS Law Group to Discuss Your Rights - GRTS | Press release | PR Newswire | +1.93% | +3.55% | |
| Form 8-K Gritstone bio, Inc. For: Jun 25 | SEC filing · Form 8-K | SEC EDGAR | +0.97% | -2.78% | |
| Form 8-K Gritstone bio, Inc. For: Jun 17 | SEC filing · Form 8-K | SEC EDGAR | +0.42% | -0.34% | |
| Gritstone bio Announces Inducement Grants Under Nasdaq Listing Rule 5635(c)(4) | Press release | GlobeNewswire | -1.11% | -0.50% | |
| Gritstone bio to Participate in Upcoming Investor and Scientific Conferences | Press release | GlobeNewswire | +1.26% | +8.00% | |
| Form DEFA14A Gritstone bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | +1.00% | -4.94% | |
| Form 10-Q Gritstone bio, Inc. For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | +0.65% | -7.72% | |
| Form 8-K Gritstone bio, Inc. For: May 09 | SEC filing · Form 8-K | SEC EDGAR | +0.65% | -7.72% | |
| Gritstone bio Reports First Quarter 2024 Financial Results and Provides Corporate Updates | Press release | GlobeNewswire | +0.65% | -7.72% | |
| Gritstone bio to Report First Quarter 2024 Financial Results and Provide Corporate Updates on May 9, 2024 | Press release | GlobeNewswire | -0.62% | +6.42% | |
| Gritstone bio Highlights the Durability and Potential Broad Utility of its Self-amplifying mRNA (samRNA) COVID-19 Vaccine at ESCMID Global 2024 | Press release | GlobeNewswire | -1.28% | -2.44% | |
| Form 8-K Gritstone bio, Inc. For: Apr 24 | SEC filing · Form 8-K | SEC EDGAR | +2.11% | -1.72% | |
| Form ARS Gritstone bio, Inc. For: Dec 31 | SEC filing · Form ARS | SEC EDGAR | -1.28% | -2.44% | |
| Form DEF 14A Gritstone bio, Inc. For: Jun 17 | SEC filing · Form DEF | SEC EDGAR | -1.28% | -2.44% | |
| Form DEFA14A Gritstone bio, Inc. | SEC filing · Form DEFA14A | SEC EDGAR | -1.28% | -2.44% | |
| Gritstone bio Announces Appointment of Stephen Webster to its Board of Directors | Press release | GlobeNewswire | +2.11% | -1.72% | |
| Nature Medicine Publishes Interim Results from Gritstone bio’s Phase 1/2 Study of “Off-the-Shelf” Neoantigen Vaccine Platform (SLATE) | Press release | GlobeNewswire | -0.90% | -13.83% | |
| Gritstone bio Presents Improvements to EDGE™ Platform at AACR 2024 | Press release | GlobeNewswire | +3.00% | +1.00% | |
| Gritstone bio to Participate in Upcoming Investor and Scientific Conferences | Press release | GlobeNewswire | +3.00% | +1.00% | |
| Form 8-K Gritstone bio, Inc. For: Apr 01 | SEC filing · Form 8-K | SEC EDGAR | -0.84% | -2.46% | |
| Form 8-K Gritstone bio, Inc. For: Apr 01 | SEC filing · Form 8-K | SEC EDGAR | -0.81% | -7.69% | |
| Gritstone bio Announces Positive Preliminary Progression-free Survival and Long-term Circulating Tumor DNA (ctDNA) Data from Phase 2 Portion of Ongoing Phase 2/3 Study of its Personalized Cancer Vaccine, GRANITE, in Front-line Metastatic Microsatellite St | Press release | GlobeNewswire | -0.81% | -7.69% | |
| Gritstone bio Announces Pricing of $32.5 Million Underwritten Public Offering | Press release | GlobeNewswire | -0.81% | -7.69% | |
| Gritstone bio Announces Proposed Public Offering | Press release | GlobeNewswire | -0.81% | -7.69% | |
| Form 10-K Gritstone bio, Inc. For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | -0.96% | +1.40% | |
| Form 8-K Gritstone bio, Inc. For: Mar 05 | SEC filing · Form 8-K | SEC EDGAR | -0.96% | +1.40% | |
| Form S-8 Gritstone bio, Inc. | SEC filing · Form S-8 | SEC EDGAR | -0.96% | +1.40% | |
| Gritstone bio Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Corporate Updates | Press release | GlobeNewswire | -0.96% | +1.40% | |
| Form 8-K Gritstone bio, Inc. For: Feb 29 | SEC filing · Form 8-K | SEC EDGAR | -11.82% | -3.81% | |
| Gritstone bio Announces Workforce Reduction | Press release | GlobeNewswire | -11.82% | -3.81% | |
| Gritstone bio to Participate in Upcoming Investor and Scientific Conferences | Press release | GlobeNewswire | +0.24% | -1.89% | |
| Form 8-K Gritstone bio, Inc. For: Feb 12 | SEC filing · Form 8-K | SEC EDGAR | +1.56% | +0.45% | |
| Gritstone bio Announces Update to Comparative Phase 2b COVID-19 Clinical Trial | Press release | GlobeNewswire | +1.56% | +0.45% | |
| Gritstone bio Announces Inducement Grants Under Nasdaq Listing Rule 5635(c)(4) | Press release | GlobeNewswire | -0.66% | -1.32% | |
| Gritstone bio to Participate in Upcoming Investor Conference | Press release | GlobeNewswire | -1.06% | +2.11% | |
| Gritstone bio Announces Inducement Grants Under Nasdaq Listing Rule 5635(c)(4) | Press release | GlobeNewswire | -1.62% | -3.24% | |
| Form EFFECT Gritstone bio, Inc. | SEC filing · Form EFFECT | SEC EDGAR | -0.73% | +5.83% | |
| Form S-3 Gritstone bio, Inc. | SEC filing · Form S-3 | SEC EDGAR | +2.14% | +9.63% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the GRTS section they belong to.
Where else GRTS is measured.
GRTS earnings → · Analyst actions → · SEC filings →
Other Healthcare names, measured the same way
| Ticker | Events | Median 30-min | % positive |
|---|---|---|---|
| Brainstorm Cell Therapeutics Inc. (BCLI) | 660 | 0.00% | 47% |
| OPHTHOTECH CORP COMMON (OPHT) | 660 | -0.20% | 43% |
| Inovio Pharmaceuticals, Inc. (INO) | 658 | -0.29% | 43% |
| VistaGen Therapeutics, Inc. (VTGN) | 658 | +0.16% | 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 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 Gritstone bio, Inc.'s median reaction calculated?
Every labeled GRTS 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 659 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. 50% of GRTS'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 GRTS'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.