Masimo Corporation (MASI)
MASI moved a median of -0.07% 30 minutes after news, and -0.20% by the close. How MASI actually reacts to news — the realized, point-in-time move the market made, measured across 1,042 labeled events over the last three years with zero look-ahead.
MASI’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | -0.04% | 42% | 1,008 |
| 30-min | -0.07% | 42% | 1,010 |
| 60-min | -0.13% | 43% | 1,010 |
| to close | -0.20% | 43% | 1,006 |
| Middle 50% of MASI reactions | -0.56% to +0.38% |
|---|---|
| Median reaction (30-min) | -0.07% |
| Measured reactions | 1,042 |
Half of all Masimo Corporation news events land between -0.56% and +0.38% at 30 minutes.
Reaction stats as of 2026-08-31. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How MASI reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst upgrades | 21 | -0.08% | 43% | -0.89% |
| Analyst downgrades | 26 | +0.08% | 58% | +0.37% |
| Rating reiterations | 56 | -0.32% | 41% | +0.05% |
| Price-target raises | 15 | -0.46% | 40% | +0.50% |
Last 3 years, pulled 2026-08-31. 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 MASI ranks against every other measured name →
That’s how MASI usually reacts — get an email when it moves on news →Email me when MASI moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to MASI's baseline. Nothing else.
Recent MASI events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Form 15-12G MASIMO CORP | SEC filing · Form 15-12G | SEC EDGAR | — | — | |
| Form 8-K MASIMO CORP For: Jun 10 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form POSASR MASIMO CORP | SEC filing · Form POSASR | SEC EDGAR | — | — | |
| Form S-8 POS MASIMO CORP | SEC filing · Form S-8 | SEC EDGAR | — | — | |
| Sirius XM Holdings Set to Join S&P MidCap 400 | Press release | PR Newswire | +0.01% | +0.00% | |
| Form SD MASIMO CORP | SEC filing · Form SD | SEC EDGAR | +0.01% | -0.07% | |
| Form 10-Q MASIMO CORP For: Apr 04 | SEC filing · Form 10-Q | SEC EDGAR | -0.05% | -0.03% | |
| Form 8-K MASIMO CORP For: May 01 | SEC filing · Form 8-K | SEC EDGAR | +0.01% | -0.12% | |
| Masimo Shareholders Approve Acquisition by Danaher | Press release | Business Wire | +0.01% | -0.12% | |
| Form 10-K/A MASIMO CORP For: Jan 03 | SEC filing · Form 10-K | SEC EDGAR | +0.01% | -0.12% | |
| Masimo SET® Pulse Oximetry Performed Accurately on Hospitalized Newborns of All Skin Tones in Largest-Ever Prospective Real-World Study | Press release | Business Wire | -0.01% | -0.10% | |
| Form 8-K MASIMO CORP For: Apr 23 | SEC filing · Form 8-K | SEC EDGAR | +0.03% | +0.07% | |
| Form DEFA14A MASIMO CORP | SEC filing · Form DEFA14A | SEC EDGAR | +0.03% | +0.07% | |
| Halper Sadeh LLC is Investigating Whether MASI, CRBG, MKC, WBD are Obtaining Fair Deals for their Shareholders | Press release | GlobeNewswire | -0.05% | +0.33% | |
| Form DEFM14A MASIMO CORP | SEC filing · Form DEFM14A | SEC EDGAR | -0.04% | +0.08% | |
| Form PREM14A MASIMO CORP For: Mar 18 | SEC filing · Form PREM14A | SEC EDGAR | -0.08% | +0.31% | |
| BRODSKY & SMITH SHAREHOLDER UPDATE: Notifying Investors of the Following Investigations: Masimo Corporation (Nasdaq – MASI), IHS Holding Limited (NYSE – HIS), VerifyMe, Inc. (Nasdaq – VRME), Great Lakes Dredge & Dock Corporation (Nasdaq – GLDD) | Press release | GlobeNewswire | — | -0.07% | |
| Form 10-K MASIMO CORP For: Jan 03 | SEC filing · Form 10-K | SEC EDGAR | -0.01% | +0.06% | |
| Are MASI, KW, VRME, BKKT Obtaining Fair Deals for their Shareholders? | Press release | PR Newswire | +0.05% | +0.46% | |
| BRODSKY & SMITH SHAREHOLDER UPDATE: Notifying Investors of the Following Investigations: Masimo Corporation (Nasdaq - MASI), IHS Holding Limited (NYSE – HIS), VerifyMe, Inc. (Nasdaq - VRME), Great Lakes Dredge & Dock Corporation (Nasdaq - GLDD) | Press release | GlobeNewswire | -0.01% | -0.15% | |
| Form 8-K MASIMO CORP For: Feb 16 | SEC filing · Form 8-K | SEC EDGAR | -0.06% | -0.18% | |
| Form DEFA14A MASIMO CORP | SEC filing · Form DEFA14A | SEC EDGAR | -0.06% | -0.18% | |
| MASI Alert: Monsey Firm of Wohl & Fruchter Investigating Fairness of the Sale of Masimo Corporation to Danaher Corporation | Press release | GlobeNewswire | -0.04% | +0.07% | |
| MASI Stock Alert: Halper Sadeh LLC is Investigating Whether Masimo Corporation is Obtaining a Fair Price for Its Shareholders | Press release | Business Wire | -0.26% | -0.28% | |
| Masimo to be Acquired by Danaher for $180.00 Per Share | Press release | Business Wire | -0.06% | -0.18% | |
| Halper Sadeh LLC Encourages Masimo Corporation Shareholders to Contact the Firm to Discuss Their Rights | Press release | GlobeNewswire | -0.55% | +0.03% | |
| Masimo to Report Fourth Quarter and Full Year 2025 Financial Results after Market Close on Thursday, February 26 | Press release | Business Wire | -0.33% | -1.54% | |
| Clairity Appoints Founder Dr. Connie Lehman as Chief Executive Officer; Joe Kiani Named Chairman of the Board | Press release | GlobeNewswire | -0.51% | -1.65% | |
| Form 8-K MASIMO CORP For: Jan 12 | SEC filing · Form 8-K | SEC EDGAR | -0.63% | -5.45% | |
| Masimo Announces Select Preliminary 2025 Financial Results | Press release | Business Wire | -0.63% | -5.45% | |
| Masimo to Present in the J.P. Morgan 2026 Healthcare Conference | Press release | Business Wire | +0.29% | +0.18% | |
| HALPER SADEH LLC ENCOURAGES MASIMO CORPORATION SHAREHOLDERS TO CONTACT THE FIRM TO DISCUSS THEIR RIGHTS | Press release | PR Newswire | +0.08% | +0.05% | |
| Form 8-K MASIMO CORP For: Dec 03 | SEC filing · Form 8-K | SEC EDGAR | -0.74% | +2.89% | |
| Masimo Hosts 2025 Investor Day and Details Strategic Roadmap for Durable Growth | Press release | Business Wire | -0.74% | +2.89% | |
| Form 8-K MASIMO CORP For: Dec 01 | SEC filing · Form 8-K | SEC EDGAR | +0.38% | -1.15% | |
| Knobbe Martens Guides Masimo to $634M Win Against Apple in Patent Infringement Case | Press release | PR Newswire | +0.01% | -1.16% | |
| Masimo Issues Statement on California Jury Verdict Finding Patent Infringement by Apple and Awarding Masimo $634 Million in Damages | Press release | Business Wire | -1.53% | -3.44% | |
| Clairity Raises $43 Million in Series B to Launch First FDA-Authorized AI Platform for Breast Cancer Risk Prediction | Press release | Business Wire | -0.06% | — | |
| Form 10-Q MASIMO CORP For: Sep 27 | SEC filing · Form 10-Q | SEC EDGAR | +0.95% | -5.86% | |
| Form 8-K MASIMO CORP For: Nov 04 | SEC filing · Form 8-K | SEC EDGAR | +0.95% | -5.86% | |
| Masimo Reports Third Quarter 2025 Results | Press release | Business Wire | +0.95% | -5.86% | |
| Halper Sadeh LLC Encourages Masimo Corporation Shareholders to Contact the Firm to Discuss Their Rights | Press release | Business Wire | +0.01% | -0.17% | |
| Masimo to Report Third Quarter 2025 Financial Results after Market Close on Tuesday, November 4 | Press release | Business Wire | +0.00% | +0.91% | |
| Masimo to Host Investor Day on December 3, 2025 | Press release | Business Wire | +0.45% | -2.94% | |
| In Feasibility Study for Large, Prospective, Real-World Trial, Masimo SET® Performed Accurately on Critically Ill Adult ICU Patients of All Skin Tones | Press release | Business Wire | -0.08% | +0.60% | |
| Form 8-K MASIMO CORP For: Sep 23 | SEC filing · Form 8-K | SEC EDGAR | +0.23% | +3.38% | |
| Form 8-K MASIMO CORP For: Sep 23 | SEC filing · Form 8-K | SEC EDGAR | +0.84% | -1.03% | |
| HARMAN Completes Sound United Acquisition to Expand Premium Audio Leadership | Press release | Business Wire | +0.84% | -1.03% | |
| Masimo Completes Sale of Consumer Audio Business to HARMAN International | Press release | Business Wire | +0.84% | -1.03% | |
| New Study Finds That Using Masimo Technologies to Continuously Monitor General Floor Patients Reduces Costs | Press release | Business Wire | -0.09% | -1.89% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the MASI section they belong to.
Where else MASI is measured.
MASI earnings → · Analyst actions → · SEC filings →
Other Healthcare names, measured the same way
| Ticker | Events | Median 30-min | % positive |
|---|---|---|---|
| VIVUS (VVUS) | 1,044 | -0.36% | 41% |
| Integer Holdings Corporation (ITGR) | 1,043 | 0.00% | 49% |
| GraniteShares YieldBOOST CRCL ETF (CRY) | 1,038 | 0.00% | 49% |
| Savara, Inc. (SVRA) | 1,031 | 0.00% | 46% |
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 Masimo Corporation's median reaction calculated?
Every labeled MASI 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 1,042 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. 42% of MASI'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 2026-08-31.
Does MASI'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.