Harpoon Therapeutics, Inc. (HARP)
HARP moved a median of 0.00% 30 minutes after news, and 0.00% by the close. How HARP actually reacts to news — the realized, point-in-time move the market made, measured across 131 labeled events over the last three years with zero look-ahead.
HARP’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | 0.00% | 45% | 95 |
| 30-min | 0.00% | 48% | 95 |
| 60-min | 0.00% | 47% | 95 |
| to close | 0.00% | 47% | 97 |
| Middle 50% of HARP reactions | -1.64% to +0.27% |
|---|---|
| Median reaction (30-min) | 0.00% |
| Measured reactions | 131 |
Half of all Harpoon Therapeutics, Inc. news events land between -1.64% and +0.27% at 30 minutes.
Reaction stats as of 2026-08-31. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
Email me when HARP moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to HARP's baseline. Nothing else.
Recent HARP events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Seismic Therapeutic Appoints Julie Eastland as Independent Board Director | Press release | Business Wire | — | — | |
| Form 15-12G Harpoon Therapeutics, | SEC filing · Form 15-12G | SEC EDGAR | — | — | |
| Form EFFECT Harpoon Therapeutics, | SEC filing · Form EFFECT | SEC EDGAR | — | — | |
| Form 8-K Harpoon Therapeutics, For: Mar 11 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form POS AM Harpoon Therapeutics, | SEC filing · Form POS | SEC EDGAR | — | — | |
| Form S-8 POS Harpoon Therapeutics, | SEC filing · Form S-8 | SEC EDGAR | — | — | |
| Form 8-K Harpoon Therapeutics, For: Mar 08 | SEC filing · Form 8-K | SEC EDGAR | — | — | |
| Form 8-K Harpoon Therapeutics, For: Feb 28 | SEC filing · Form 8-K | SEC EDGAR | +0.04% | +0.04% | |
| Form DEFA14A Harpoon Therapeutics, | SEC filing · Form DEFA14A | SEC EDGAR | +0.04% | +0.04% | |
| Form 8-K Harpoon Therapeutics, For: Feb 21 | SEC filing · Form 8-K | SEC EDGAR | +0.04% | +0.13% | |
| Form DEFA14A Harpoon Therapeutics, | SEC filing · Form DEFA14A | SEC EDGAR | +0.04% | +0.13% | |
| Form DEFM14A Harpoon Therapeutics, | SEC filing · Form DEFM14A | SEC EDGAR | -0.13% | -0.18% | |
| INVESTIGATION ALERT: Halper Sadeh LLC Investigates HARP, JNPR, TGAN, TAST | Press release | PR Newswire | -0.09% | -0.09% | |
| INVESTIGATION ALERT: Halper Sadeh LLC Investigates HARP, TARO, FFNW | Press release | GlobeNewswire | -0.04% | -0.09% | |
| Form 8-K Harpoon Therapeutics, For: Jan 26 | SEC filing · Form 8-K | SEC EDGAR | +0.11% | -0.13% | |
| Form PREM14A Harpoon Therapeutics, For: Jan 29 | SEC filing · Form PREM14A | SEC EDGAR | +0.11% | -0.13% | |
| Form 8-K Harpoon Therapeutics, For: Jan 25 | SEC filing · Form 8-K | SEC EDGAR | -0.09% | +0.00% | |
| SHAREHOLDER NOTICE: Halper Sadeh LLC Investigates HARP, JNPR, TGAN | Press release | PR Newswire | -0.02% | +0.02% | |
| ALERT: Juan Monteverde Encourages the Shareholders of PGTI, WAVD, HARP, VIA to Take Action | Press release | PR Newswire | -0.04% | +0.22% | |
| SHAREHOLDER RIGHTS INVESTIGATION: Halper Sadeh LLC Investigates HARP, AMAM, AXNX, CPE | Press release | Accesswire | +0.31% | +0.00% | |
| SHAREHOLDER INVESTIGATION: Halper Sadeh LLC Investigates HARP, AMAM, AXNX | Press release | Accesswire | +0.00% | +0.18% | |
| Form 8-K Harpoon Therapeutics, For: Jan 07 | SEC filing · Form 8-K | SEC EDGAR | -0.07% | +0.45% | |
| Form DEFA14A Harpoon Therapeutics, | SEC filing · Form DEFA14A | SEC EDGAR | -0.07% | +0.45% | |
| HARP Alert: Monsey Firm of Wohl & Fruchter Investigating Fairness of the Sale of Harpoon Therapeutics to Merck | Press release | GlobeNewswire | -0.07% | +0.45% | |
| HARP Stock Alert: Halper Sadeh LLC Is Investigating Whether the Sale of Harpoon Therapeutics, Inc. Is Fair to Shareholders | Press release | Business Wire | -0.07% | +0.45% | |
| Form S-8 Harpoon Therapeutics, | SEC filing · Form S-8 | SEC EDGAR | -0.07% | +0.45% | |
| Harpoon Therapeutics Strengthens Leadership Team | Press release | GlobeNewswire | -0.85% | -2.76% | |
| Form EFFECT Harpoon Therapeutics, | SEC filing · Form EFFECT | SEC EDGAR | -1.96% | -0.82% | |
| Harpoon Therapeutics Abstract for HPN328 Accepted for Rapid Oral Presentation at the 2024 American Society of Clinical Oncology Genitourinary Cancers Symposium | Press release | GlobeNewswire | +2.51% | +4.64% | |
| Harpoon Therapeutics Presents HPN217 Phase 1 Clinical Data in Relapsed/Refractory Multiple Myeloma (RRMM) at ASH 2023 and Announces Selection of Recommended Phase 2 Dose (RP2D) | Press release | GlobeNewswire | +3.61% | -7.11% | |
| Form S-3 Harpoon Therapeutics, | SEC filing · Form S-3 | SEC EDGAR | +0.57% | +5.55% | |
| Form 8-K Harpoon Therapeutics, For: Nov 26 | SEC filing · Form 8-K | SEC EDGAR | -1.05% | -1.15% | |
| Form 8-K Harpoon Therapeutics, For: Nov 24 | SEC filing · Form 8-K | SEC EDGAR | — | +0.00% | |
| Form 10-Q Harpoon Therapeutics, For: Sep 30 | SEC filing · Form 10-Q | SEC EDGAR | +4.58% | +3.43% | |
| Form 8-K Harpoon Therapeutics, For: Nov 09 | SEC filing · Form 8-K | SEC EDGAR | +4.58% | +3.43% | |
| Harpoon Therapeutics Reports Third Quarter 2023 Financial Results and Provides Corporate Update | Press release | GlobeNewswire | +4.58% | +3.43% | |
| Harpoon Therapeutics Abstract for HPN217 Accepted for Presentation at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition | Press release | GlobeNewswire | +0.44% | +2.18% | |
| Form D Harpoon Therapeutics, | SEC filing · Form D | SEC EDGAR | +1.45% | +4.35% | |
| Form 8-K Harpoon Therapeutics, For: Oct 22 | SEC filing · Form 8-K | SEC EDGAR | +1.55% | +6.77% | |
| Form 8-K Harpoon Therapeutics, For: Oct 23 | SEC filing · Form 8-K | SEC EDGAR | -7.92% | -25.32% | |
| Harpoon Therapeutics Announces Up to $150 Million Private Placement | Press release | GlobeNewswire | -7.92% | -25.32% | |
| Harpoon Therapeutics Announces Updated Interim Tolerability and Response Data from Phase 1/2 Clinical Trial of T Cell Engager HPN328 at ESMO Congress 2023 | Press release | GlobeNewswire | -7.92% | -25.32% | |
| Harpoon Therapeutics to Host Webcast Reviewing HPN328 Interim Data Presented at ESMO Congress 2023 on October 23, 2023 | Press release | GlobeNewswire | +0.00% | +27.99% | |
| Harpoon Therapeutics to Present Interim Tolerability and Response Data from Phase 1/2 Clinical Trial of T Cell Engager HPN328 at ESMO Congress 2023 | Press release | GlobeNewswire | +0.62% | +1.86% | |
| Form 8-K Harpoon Therapeutics, For: Sep 27 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | +1.75% | |
| Harpoon Therapeutics Presents HPN217 Interim Phase 1 Data at the IMS Annual Meeting | Press release | GlobeNewswire | +0.00% | +1.22% | |
| Harpoon Therapeutics Announces First Patients with Small Cell Lung Cancer Dosed in HPN328 Combination Cohort | Press release | GlobeNewswire | +0.02% | -6.83% | |
| Form 8-K Harpoon Therapeutics, For: Sep 12 | SEC filing · Form 8-K | SEC EDGAR | -4.58% | -14.69% | |
| Harpoon Therapeutics Provides an Update on the HPN217 Development and Option Agreement with AbbVie | Press release | GlobeNewswire | -4.58% | -14.69% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the HARP section they belong to.
Where else HARP is measured.
HARP earnings → · Analyst actions → · SEC filings →
Every ticker we measure the same way24
Apple (AAPL)
How AAPL actually reacts to news, measured.
NVIDIA (NVDA)
How NVDA actually reacts to news, measured.
Tesla (TSLA)
How TSLA actually reacts to news, measured.
Microsoft (MSFT)
How MSFT actually reacts to news, measured.
Advanced Micro Devices (AMD)
How AMD actually reacts to news, measured.
Amazon (AMZN)
How AMZN actually reacts to news, measured.
Alphabet (GOOG)
How GOOG actually reacts to news, measured.
Meta Platforms (META)
How META actually reacts to news, measured.
Broadcom (AVGO)
How AVGO actually reacts to news, measured.
JPMorgan Chase (JPM)
How JPM actually reacts to news, measured.
Visa (V)
How V actually reacts to news, measured.
Walmart (WMT)
How WMT actually reacts to news, measured.
Eli Lilly (LLY)
How LLY actually reacts to news, measured.
UnitedHealth Group (UNH)
How UNH actually reacts to news, measured.
Netflix (NFLX)
How NFLX actually reacts to news, measured.
Johnson & Johnson (JNJ)
How JNJ actually reacts to news, measured.
Exxon Mobil (XOM)
How XOM actually reacts to news, measured.
Home Depot (HD)
How HD actually reacts to news, measured.
Costco (COST)
How COST actually reacts to news, measured.
Mastercard (MA)
How MA actually reacts to news, measured.
Oracle (ORCL)
How ORCL actually reacts to news, measured.
Salesforce (CRM)
How CRM actually reacts to news, measured.
Bank of America (BAC)
How BAC actually reacts to news, measured.
Coca-Cola (KO)
How KO actually reacts to news, measured.
Walt Disney (DIS)
How DIS actually reacts to news, measured.
Browse all tickers
Every name we’ve measured, in one place.
How the numbers are made.
How is Harpoon Therapeutics, Inc.'s median reaction calculated?
Every labeled HARP 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 131 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. 48% of HARP'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 HARP'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.