Arm Holdings plc - American Depositary Shares (ARM)
ARM moved a median of +0.42% 30 minutes after news, and +1.09% by the close. How ARM actually reacts to news — the realized, point-in-time move the market made, measured across 184 labeled events over the last three years with zero look-ahead.
ARM’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | +0.20% | 56% | 182 |
| 30-min | +0.42% | 59% | 182 |
| 60-min | +0.41% | 57% | 182 |
| to close | +1.09% | 62% | 182 |
| Middle 50% of ARM reactions | -0.91% to +2.69% |
|---|---|
| Median reaction (30-min) | +0.42% |
| Measured reactions | 184 |
Half of all Arm Holdings plc - American Depositary Shares news events land between -0.91% and +2.69% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How ARM reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst upgrades | 31 | -0.53% | 42% | +1.07% |
| Analyst downgrades | 25 | -0.88% | 32% | -1.56% |
| Coverage initiations | 98 | +1.49% | 70% | -0.13% |
| Rating reiterations | 210 | -0.06% | 49% | -0.18% |
| Price-target raises | 79 | +0.19% | 54% | +0.37% |
| Price-target cuts | 34 | -0.09% | 41% | -0.74% |
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. See how ARM ranks against every other measured name →
That’s how ARM usually reacts — get an email when it moves on news →Email me when ARM moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to ARM's baseline. Nothing else.
Recent ARM events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Form 6-K ARM HOLDINGS PLC /UK For: Sep 18 | SEC filing · Form 6-K | SEC EDGAR | +1.37% | +9.75% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Sep 10 | SEC filing · Form 6-K | SEC EDGAR | -0.64% | +2.97% | |
| Arm Holdings plc Reports Results for the First Quarter of the Fiscal Year Ending 2027 | Press release | Business Wire | -3.71% | -7.03% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Jul 29 | SEC filing · Form 6-K | SEC EDGAR | -3.71% | -7.03% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Jun 30 | SEC filing · Form 6-K | SEC EDGAR | -3.71% | -7.03% | |
| Arm Announces Earnings Release Date for First Quarter Fiscal Year Ended 2027 | Press release | Business Wire | +2.43% | +0.80% | |
| Bronstein, Gewirtz & Grossman, LLC Initiates an Investigation into Allegations Against Arm Holdings plc (ARM) And Encourages Shareholders to Reach Out | Press release | ACCESS Newswire | -0.79% | -6.02% | |
| Bronstein, Gewirtz & Grossman, LLC Announces an Investigation Against Arm Holdings plc (ARM) and Encourages Shareholders to Learn More About the Investigation | Press release | ACCESS Newswire | -0.17% | +1.73% | |
| Bronstein, Gewirtz & Grossman, LLC Encourages Arm Holdings plc (ARM) Shareholders to Inquire about Securities Investigation | Press release | ACCESS Newswire | +0.06% | -2.38% | |
| Bronstein, Gewirtz & Grossman, LLC Encourages Arm Holdings plc (ARM) Stockholders to Inquire about Securities Investigation | Press release | ACCESS Newswire | +2.73% | +4.88% | |
| Arm Holdings plc (ARM) Investigation: Bronstein, Gewirtz & Grossman, LLC Encourages Shareholders to Contact the Firm to Learn More About the Investigation | Press release | ACCESS Newswire | +0.56% | -1.36% | |
| Bronstein, Gewirtz & Grossman, LLC Is Investigating Arm Holdings plc (ARM) And Encourages Stockholders to Connect | Press release | ACCESS Newswire | -0.40% | +1.25% | |
| Form 20-F ARM HOLDINGS PLC /UK For: Mar 31 | SEC filing · Form 20-F | SEC EDGAR | -0.29% | -5.54% | |
| Form IRANNOTICE ARM HOLDINGS PLC /UK | SEC filing · Form IRANNOTICE | SEC EDGAR | -0.29% | -5.54% | |
| Form SD ARM HOLDINGS PLC /UK | SEC filing · Form SD | SEC EDGAR | -0.29% | -5.54% | |
| Arm Holdings plc (ARM) Investigation: Bronstein, Gewirtz & Grossman, LLC Encourages Stockholders to Contact the Firm to Learn More About the Investigation | Press release | ACCESS Newswire | -2.70% | +1.17% | |
| Bronstein, Gewirtz & Grossman, LLC Announces an Investigation Against Arm Holdings plc (ARM) and Encourages Stockholders to Learn More About the Investigation | Press release | ACCESS Newswire | -2.70% | +1.17% | |
| Bronstein, Gewirtz & Grossman, LLC Encourages Arm Holdings plc (ARM) Investors to Inquire about Securities Investigation | Press release | ACCESS Newswire | +0.47% | -2.10% | |
| Form S-8 ARM HOLDINGS PLC /UK | SEC filing · Form S-8 | SEC EDGAR | -1.20% | -2.57% | |
| Arm Holdings plc Reports Results for the Fourth Quarter and Fiscal Year Ended 2026 | Press release | Business Wire | +4.09% | -3.91% | |
| Form 6-K ARM HOLDINGS PLC /UK For: May 06 | SEC filing · Form 6-K | SEC EDGAR | +4.09% | -3.91% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Apr 21 | SEC filing · Form 6-K | SEC EDGAR | +0.84% | +0.28% | |
| Arm Announces Earnings Release Date for Fourth Quarter Fiscal Year Ended 2026 | Press release | Business Wire | -0.12% | -1.95% | |
| Arm Expands Compute Platform to Silicon Products in Historic Company First | Press release | Business Wire | -0.97% | -2.70% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Mar 24 | SEC filing · Form 6-K | SEC EDGAR | +0.37% | -1.25% | |
| Arm Holdings plc Reports Results for the Third Quarter of the Fiscal Year Ending 2026 | Press release | Business Wire | -0.88% | +6.62% | |
| Arm to Host ‘Arm Everywhere’ Event and Webcast | Press release | Business Wire | -0.88% | +6.62% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Dec 31 | SEC filing · Form 6-K | SEC EDGAR | -0.88% | +6.62% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Feb 04 | SEC filing · Form 6-K | SEC EDGAR | -0.88% | +6.62% | |
| Arm Announces Earnings Release Date for Third Quarter Fiscal Year Ended 2026 | Press release | Business Wire | +0.27% | +0.65% | |
| Arm Holdings plc Reports Results for the Second Quarter of the Fiscal Year Ending 2026 | Press release | Business Wire | -4.19% | -5.24% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Nov 05 | SEC filing · Form 6-K | SEC EDGAR | -4.19% | -5.24% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Sep 30 | SEC filing · Form 6-K | SEC EDGAR | -4.19% | -5.24% | |
| Arm Announces Earnings Release Date for Second Quarter Fiscal Year Ended 2026 | Press release | Business Wire | +0.64% | +0.50% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Sep 18 | SEC filing · Form 6-K | SEC EDGAR | -1.20% | -1.83% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Sep 10 | SEC filing · Form 6-K | SEC EDGAR | +2.25% | +1.11% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Aug 11 | SEC filing · Form 6-K | SEC EDGAR | -0.35% | — | |
| Arm Holdings plc Reports Results for the First Quarter of the Fiscal Year Ending 2026 | Press release | Business Wire | -4.42% | -4.48% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Jul 30 | SEC filing · Form 6-K | SEC EDGAR | -4.42% | -4.48% | |
| Form 6-K ARM HOLDINGS PLC /UK For: Jun 30 | SEC filing · Form 6-K | SEC EDGAR | -4.42% | -4.48% | |
| Arm Announces Earnings Release Date for First Quarter Fiscal Year Ended 2026 | Press release | Business Wire | -0.41% | -4.36% | |
| Form 20-F ARM HOLDINGS PLC /UK For: Mar 31 | SEC filing · Form 20-F | SEC EDGAR | -1.68% | -7.29% | |
| Form IRANNOTICE ARM HOLDINGS PLC /UK | SEC filing · Form IRANNOTICE | SEC EDGAR | -1.68% | -7.29% | |
| Form S-8 ARM HOLDINGS PLC /UK | SEC filing · Form S-8 | SEC EDGAR | -1.68% | -7.29% | |
| Arm Holdings plc Reports Results for the Fourth Quarter and Fiscal Year Ended 2025 | Press release | Business Wire | -3.85% | -2.31% | |
| Form 6-K ARM HOLDINGS PLC /UK For: May 07 | SEC filing · Form 6-K | SEC EDGAR | -3.85% | -2.31% | |
| Arm Announces Earnings Release Date for Fourth Quarter and Fiscal Year Ended 2025 | Press release | Business Wire | +1.29% | +24.13% | |
| GraniteShares ETFs Announces Name Change and Investment Objectives on some of its Short and Leveraged ETFs | Press release | GlobeNewswire | -0.18% | -0.18% | |
| Brex Grows Enterprise Business 80% as Anthropic, Arm, Robinhood, ServiceTitan, Sonos, Wiz, and More Select Brex as their Modern Spend Platform | Press release | PR Newswire | -0.11% | -2.41% | |
| Arm Holdings plc Reports Results for the Third Quarter of the Fiscal Year Ended 2025 | Press release | Business Wire | -1.50% | +3.38% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the ARM section they belong to.
Where else ARM is measured.
ARM earnings → · Analyst actions → · SEC filings →
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How the numbers are made.
How is Arm Holdings plc - American Depositary Shares's median reaction calculated?
Every labeled ARM 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 184 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. 59% of ARM'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 ARM'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.