System1, Inc. Class A (SST)
SST moved a median of -0.04% 30 minutes after news, and -0.88% by the close. How SST actually reacts to news — the realized, point-in-time move the market made, measured across 294 labeled events over the last three years with zero look-ahead.
SST’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | 0.00% | 33% | 293 |
| 30-min | -0.04% | 43% | 294 |
| 60-min | 0.00% | 48% | 294 |
| to close | -0.88% | 42% | 293 |
| Middle 50% of SST reactions | -2.43% to +2.32% |
|---|---|
| Median reaction (30-min) | -0.04% |
| Measured reactions | 294 |
Half of all System1, Inc. Class A news events land between -2.43% and +2.32% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
Email me when SST moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to SST's baseline. Nothing else.
Recent SST events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| MapQuest Adds Public Transit Directions, Helping Travelers Plan Complete Trips by Bus, Train, and More | Press release | Business Wire | +0.95% | -2.22% | |
| System1’s MapQuest Surpasses 2 Million New Users Over the Past Week | Press release | Business Wire | -3.46% | +23.76% | |
| MapQuest Tops the Charts at No. 1 Overall Free App in the U.S. and Canada Apple App Stores | Press release | Business Wire | +2.84% | +15.44% | |
| MapQuest Surges to No. 1 in the Apple App Store, 30 Years After Inventing Online Mapping | Press release | Business Wire | +2.28% | +14.29% | |
| Form EFFECT System1, Inc. | SEC filing · Form EFFECT | SEC EDGAR | -0.73% | -1.76% | |
| Form 10-Q System1, Inc. For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | +0.61% | +0.61% | |
| Form 8-K System1, Inc. For: Aug 05 | SEC filing · Form 8-K | SEC EDGAR | +0.61% | +0.61% | |
| MapQuest Opens Its Mapping Platform to AI Agents with a New Model Context Protocol (MCP) Server, Plus 1 Billion Free Transactions to Celebrate | Press release | Business Wire | +0.52% | -12.04% | |
| System1 Announces Second Quarter 2026 Financial Results and Launch of New Agentic Products | Press release | Business Wire | +0.61% | +0.61% | |
| Form S-3 System1, Inc. | SEC filing · Form S-3 | SEC EDGAR | +0.52% | -12.04% | |
| Form 8-K System1, Inc. For: Jul 22 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | -1.08% | |
| System1 Launches Dogpile Fetch, a New Search MCP Server From the Internet’s Original Metasearch Engine, Giving AI Agents a Wider View of the Web | Press release | Business Wire | -2.26% | +2.26% | |
| System1 to Report Second Quarter 2026 Financial Results | Press release | Business Wire | -2.26% | +2.26% | |
| Form S-8 System1, Inc. | SEC filing · Form S-8 | SEC EDGAR | +3.52% | +10.57% | |
| Form DEF 14A System1, Inc. For: Jul 22 | SEC filing · Form DEF | SEC EDGAR | +3.05% | -1.79% | |
| Form PRE 14A System1, Inc. For: Jun 10 | SEC filing · Form PRE | SEC EDGAR | +0.00% | +0.00% | |
| Form 8-K System1, Inc. For: May 29 | SEC filing · Form 8-K | SEC EDGAR | -1.33% | +17.00% | |
| System1 Strengthens Capital Structure and Reduces Total Debt Through Exchange Transaction With Lenders | Press release | Business Wire | -1.33% | +17.00% | |
| Form 10-Q System1, Inc. For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | -9.41% | -5.11% | |
| Form 8-K System1, Inc. For: May 12 | SEC filing · Form 8-K | SEC EDGAR | -9.41% | -5.11% | |
| System1 Announces First Quarter 2026 Financial Results | Press release | Business Wire | -9.41% | -5.11% | |
| MapQuest and iHeartRadio Launch First-Ever Audio Integration on MapQuest.com | Press release | Business Wire | -1.39% | -8.84% | |
| Form 10-K/A System1, Inc. For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | -3.42% | +3.68% | |
| Form 10-K System1, Inc. For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | -0.41% | -13.22% | |
| Form 8-K System1, Inc. For: Mar 11 | SEC filing · Form 8-K | SEC EDGAR | -0.41% | -13.22% | |
| System1 Announces Fourth Quarter and Full Year 2025 Financial Results | Press release | Business Wire | -0.41% | -13.22% | |
| 1.org Launches Android App and Partners with Guide Dogs of America | Tender Loving Canines to Help Fund Guide and Service Dogs for Veterans, Children With Autism, and People Who Are Visually Impaired | Press release | Business Wire | +0.00% | -1.18% | |
| Form 8-K System1, Inc. For: Jan 09 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | +0.22% | |
| System1 to Participate in the 2026 ICR Conference | Press release | Business Wire | +3.33% | +0.72% | |
| Form 8-K System1, Inc. For: Dec 08 | SEC filing · Form 8-K | SEC EDGAR | -0.47% | -5.03% | |
| System1 Receives Notice of Non-Compliance with New York Stock Exchange Listing Rules | Press release | Business Wire | -0.47% | -5.03% | |
| Form 8-K System1, Inc. For: Dec 01 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | +2.35% | |
| System1 to Participate in Upcoming Investor Conferences | Press release | Business Wire | +0.00% | +0.00% | |
| 1.org, the Free Search Engine That Gives Ad Revenue to Charity, Launches with $100,000 Giving Tuesday Pledge to Support Nonprofits | Press release | Business Wire | +0.00% | +5.19% | |
| System1 to Participate in the RBC Capital Markets Global Technology, Internet, Media & Telecommunications Conference | Press release | Business Wire | +0.00% | -1.81% | |
| Form 10-Q System1, Inc. For: Sep 30 | SEC filing · Form 10-Q | SEC EDGAR | -8.46% | -13.85% | |
| Form 8-K System1, Inc. For: Nov 05 | SEC filing · Form 8-K | SEC EDGAR | -8.46% | -13.85% | |
| System1 Announces Third Quarter 2025 Financial Results | Press release | Business Wire | -8.46% | -13.85% | |
| System1 to Report Third Quarter 2025 Financial Results | Press release | Business Wire | -0.18% | -1.00% | |
| Form 10-Q System1, Inc. For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | -1.49% | +1.11% | |
| Form 8-K System1, Inc. For: Aug 07 | SEC filing · Form 8-K | SEC EDGAR | -1.49% | +1.11% | |
| System1 Announces Strong Second Quarter 2025 Financial Results | Press release | Business Wire | -1.49% | +1.11% | |
| System1 to Report Second Quarter 2025 Financial Results | Press release | Business Wire | +0.00% | +0.14% | |
| Form EFFECT System1, Inc. | SEC filing · Form EFFECT | SEC EDGAR | +0.00% | +13.69% | |
| Form S-3 System1, Inc. | SEC filing · Form S-3 | SEC EDGAR | +1.99% | -15.44% | |
| Form S-8 System1, Inc. | SEC filing · Form S-8 | SEC EDGAR | +1.99% | -15.44% | |
| Form 8-K System1, Inc. For: Jun 11 | SEC filing · Form 8-K | SEC EDGAR | -1.36% | +12.74% | |
| System1 Class A Common Stock to Begin Trading on a Split-Adjusted Basis on June 12, 2025 | Press release | Business Wire | -1.36% | +12.74% | |
| Form 8-K System1, Inc. For: Jun 10 | SEC filing · Form 8-K | SEC EDGAR | -7.12% | -7.27% | |
| System1 Announces Reverse Stock Split | Press release | Business Wire | -7.12% | -7.27% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the SST section they belong to.
Where else SST is measured.
SST earnings → · Analyst actions → · SEC filings →
Every ticker we measure the same way24
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How XOM actually reacts to news, measured.
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How HD actually reacts to news, measured.
Costco (COST)
How COST actually reacts to news, measured.
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How MA actually reacts to news, measured.
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How ORCL actually reacts to news, measured.
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How CRM actually reacts to news, measured.
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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 System1, Inc. Class A's median reaction calculated?
Every labeled SST 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 294 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. 43% of SST'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 SST'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.