Rallybio Corporation (RLYB)
RLYB moved a median of -0.24% 30 minutes after news, and -0.25% by the close. How RLYB actually reacts to news — the realized, point-in-time move the market made, measured across 186 labeled events over the last three years with zero look-ahead.
RLYB’s median reaction, across the day.
| Horizon | Median | % positive | Events |
|---|---|---|---|
| 5-min | 0.00% | 42% | 175 |
| 30-min | -0.24% | 39% | 183 |
| 60-min | -0.27% | 44% | 183 |
| to close | -0.25% | 41% | 185 |
| Middle 50% of RLYB reactions | -1.81% to +1.55% |
|---|---|
| Median reaction (30-min) | -0.24% |
| Measured reactions | 186 |
Half of all Rallybio Corporation news events land between -1.81% and +1.55% at 30 minutes.
Reaction stats as of 2026-09-21. Newest measured event . Reaction = percent move vs. the price at the news timestamp.
How RLYB reacts, by analyst action.
| Event | Events | Median 30-min | % positive | Median to close |
|---|---|---|---|---|
| Analyst downgrades | 16 | +0.56% | 69% | +5.85% |
| Rating reiterations | 44 | +0.55% | 64% | -0.69% |
| Price-target cuts | 10 | -0.38% | 30% | +1.09% |
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. 1 further class was observed with fewer than 10 measured events and is not published. See how RLYB ranks against every other measured name →
That’s how RLYB usually reacts — get an email when it moves on news →Email me when RLYB moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to RLYB's baseline. Nothing else.
Recent RLYB events, each with its measured reaction.
| Date | Headline | Event | Source | 5-min | To close |
|---|---|---|---|---|---|
| Form EFFECT Rallybio Corp | SEC filing · Form EFFECT | SEC EDGAR | — | -2.81% | |
| Form S-4/A Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | — | -0.74% | |
| Form S-4/A Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | — | -0.06% | |
| Form S-4/A Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | -0.87% | -0.87% | |
| Form 8-K Rallybio Corp For: Sep 08 | SEC filing · Form 8-K | SEC EDGAR | — | -1.88% | |
| Form S-4/A Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | +1.29% | -1.47% | |
| Form 10-Q Rallybio Corp For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | — | -0.31% | |
| Form S-4 Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | +1.05% | -1.60% | |
| Halper Sadeh LLC is Investigating Whether RLYB, KALV, INM, TMHC are Obtaining Fair Deals for their Shareholders | Press release | GlobeNewswire | -0.10% | -2.86% | |
| Form 8-K Rallybio Corp For: May 31 | SEC filing · Form 8-K | SEC EDGAR | -0.18% | +0.42% | |
| Rallybio Corporation and Avenzo Therapeutics Announce Merger Agreement to Advance Next-Generation Oncology Therapies and $215 Million Concurrent Private Placement | Press release | Business Wire | -0.18% | +0.42% | |
| RLYB Stock Alert: Halper Sadeh LLC is Investigating Whether Rallybio Corporation is Obtaining a Fair Price for its Shareholders | Press release | Business Wire | +0.46% | -2.60% | |
| Form 10-Q Rallybio Corp For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | +0.00% | -1.18% | |
| Form RW Rallybio Corp | SEC filing · Form RW | SEC EDGAR | -0.18% | +3.48% | |
| Form 8-K Rallybio Corp For: May 03 | SEC filing · Form 8-K | SEC EDGAR | -1.36% | +0.93% | |
| Form S-4/A Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | +4.07% | -0.68% | |
| Are WSR, TERN, RLYB, DAWN Obtaining Fair Deals for their Shareholders? | Press release | PR Newswire | — | +0.86% | |
| Are EWCZ, STEL, RLYB, CTRA Obtaining Fair Deals for their Shareholders? | Press release | PR Newswire | +0.61% | -0.25% | |
| Form 8-K Rallybio Corp For: Mar 31 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | -6.56% | |
| BRODSKY & SMITH SHAREHOLDER UPDATE: Notifying Investors of the Following Investigations: Rallybio Corporation (Nasdaq – RLYB), SunOpta Inc. (Nasdaq – STKL), Talkspace, Inc. (Nasdaq - TALK), Kennedy-Wilson Holdings, Inc. (Nasdaq - KW) | Press release | GlobeNewswire | +0.00% | -1.68% | |
| Form S-4 Rallybio Corp | SEC filing · Form S-4 | SEC EDGAR | +1.19% | +4.66% | |
| Form 10-K Rallybio Corp For: Dec 31 | SEC filing · Form 10-K | SEC EDGAR | +1.19% | +4.66% | |
| Are RLYB, VRME, AES Obtaining Fair Deals for their Shareholders? | Press release | PR Newswire | +0.00% | +0.97% | |
| Are KW, AES, RLYB Obtaining Fair Deals for their Shareholders? | Press release | PR Newswire | -0.27% | -0.27% | |
| Form 8-K Rallybio Corp For: Mar 01 | SEC filing · Form 8-K | SEC EDGAR | +1.18% | +7.87% | |
| Rallybio Corporation and Candid Therapeutics Announce Merger Agreement | Press release | Business Wire | +2.17% | +13.44% | |
| RLYB Stock Alert: Halper Sadeh LLC is Investigating Whether Rallybio Corporation is Obtaining a Fair Deal for its Shareholders | Press release | Business Wire | +0.93% | +12.98% | |
| Rallybio Announces Positive Data for RLYB116 Phase 1 Study Demonstrating Complete and Sustained Inhibition of Terminal Complement | Press release | Business Wire | -5.06% | -8.65% | |
| Rallybio Announces Reverse Stock Split of Common Stock | Press release | Business Wire | -4.00% | -4.13% | |
| Form 8-K Rallybio Corp For: Jan 26 | SEC filing · Form 8-K | SEC EDGAR | -4.50% | -2.71% | |
| Form DEF 14A Rallybio Corp For: Jan 26 | SEC filing · Form DEF | SEC EDGAR | -0.38% | -4.37% | |
| Form PRE 14A Rallybio Corp For: Jan 26 | SEC filing · Form PRE | SEC EDGAR | -4.84% | -3.30% | |
| Form 10-Q Rallybio Corp For: Sep 30 | SEC filing · Form 10-Q | SEC EDGAR | +2.58% | +2.17% | |
| Form 8-K Rallybio Corp For: Nov 06 | SEC filing · Form 8-K | SEC EDGAR | +2.58% | +2.17% | |
| Rallybio Reports Third Quarter 2025 Financial Results and Provides Business Updates | Press release | Business Wire | +2.58% | +2.17% | |
| Rallybio Completes Dosing of First Cohort in RLYB116 Phase 1 Confirmatory Pharmacokinetic/Pharmacodynamic Study | Press release | Business Wire | +0.19% | -1.38% | |
| Rallybio Receives $12.5 Million Equity Milestone Payment from Recursion for Advancement of REV102 Program | Press release | Business Wire | +0.07% | +5.00% | |
| Form 8-K Rallybio Corp For: Aug 26 | SEC filing · Form 8-K | SEC EDGAR | -0.02% | +7.21% | |
| Form 10-Q Rallybio Corp For: Jun 30 | SEC filing · Form 10-Q | SEC EDGAR | -2.36% | -0.18% | |
| Form 8-K Rallybio Corp For: Aug 07 | SEC filing · Form 8-K | SEC EDGAR | -2.36% | -0.18% | |
| Rallybio Reports Second Quarter 2025 Financial Results and Provides Business Updates | Press release | Business Wire | -2.36% | -0.18% | |
| Form 8-K Rallybio Corp For: Jul 08 | SEC filing · Form 8-K | SEC EDGAR | +0.71% | +24.16% | |
| Rallybio Sells Interest in REV102 Program to Recursion Pharmaceuticals | Press release | Business Wire | +0.71% | +24.16% | |
| Form 8-K Rallybio Corp For: Jun 25 | SEC filing · Form 8-K | SEC EDGAR | +3.40% | +5.30% | |
| Rallybio Initiates Dosing in RLYB116 Phase 1 Confirmatory Pharmacokinetic/Pharmacodynamic Study | Press release | Business Wire | +0.00% | -4.43% | |
| Form 8-K Rallybio Corp For: May 13 | SEC filing · Form 8-K | SEC EDGAR | +0.00% | +2.94% | |
| Form S-8 Rallybio Corp | SEC filing · Form S-8 | SEC EDGAR | -3.27% | -5.38% | |
| Form 10-Q Rallybio Corp For: Mar 31 | SEC filing · Form 10-Q | SEC EDGAR | +6.90% | +1.03% | |
| Form 8-K Rallybio Corp For: May 08 | SEC filing · Form 8-K | SEC EDGAR | +6.90% | +1.03% | |
| Rallybio Reports First Quarter 2025 Financial Results and Provides Business Updates | Press release | Business Wire | +6.90% | +1.03% |
Each reaction is the move the market actually made, measured from the news timestamp. Headlines link through to the RLYB section they belong to.
Where else RLYB is measured.
RLYB 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 Rallybio Corporation's median reaction calculated?
Every labeled RLYB 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 186 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. 39% of RLYB'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 RLYB'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.