Chai-2 / Chai-3 by Chai Discovery: status and timeline

Milestones

No announced next step

Series C funding closes14 Jul 2026Complete.

Most important, last 3 months

Chai Discovery raises $400M Series C at $3.8B valuation, deploys antibody-design AI with four pharma leaders14 Jul 2026

Current obstacles

Validation of novel designsGenerated antibodies must be synthesized and tested in the lab; computational prediction alone does not guarantee experimental success.

Physics limits

Training data determines capabilityModels can only reliably design antibodies similar to those in training data; truly novel design principles may require new experimental data.

How it works

3 parts

Training

Trained on sequence-function data

Models learn patterns from antibody sequences and their binding properties, mapping sequences to predicted traits.

Zero-shot design

Generate without templates

Predicts new sequences likely to bind targets with high affinity and stability, without structural templates.

Validation

Lab synthesis and testing

Generated sequences are synthesized and tested to validate predictions and improve models.

Spec sheet

Spec	Chai-2 / Chai-3
Series C funding	$400M^R (reported)
Post-money valuation (Series C)	$3.8B^R (reported)
Time from Series C to paid deployments	<7 months^R (reported)

^R reported by the company

Update log

1 update

Tue 14 Jul

Major: Chai Discovery raises $400M Series C at $3.8B valuation, deploys antibody-design AI with four pharma leadersPressFunding

About Chai Discovery

The team behind Chai-2 / Chai-3

Chai Discovery

AI antibody design, protein engineering, zero-shot design

Chai Discovery uses AI to design antibodies from scratch. Chai-2 achieves 16–20% hit rates across diverse targets, roughly 100x better than prior methods. Founded 2024; $400M Series C at $3.8B valuation in July 2026.

Chai-2 designs full-length antibodies with 16–20% hit rates across 52 clinical targets, ~100x improvement over prior methods.
July 2026 Series C of $400M at $3.8B valuation accelerates commercial deployment with major pharma partners.
Bypasses traditional phage display, replacing months of lab work with days of computation.

chaidiscovery.com (opens chaidiscovery.com)Company profile →

Founded: 20242 yrs
Headquarters: United States
Status: Private
Valuation: $3.8BprivateJul 2026
Raised: $630M4 rounds
Last round: Series C · $400MJul 2026
Works in: AIAI for scienceBiotech
Coverage: 2 programs · 7 updateslatest 14 Jul 2026checked 10 Oct
Lead investors: Index VenturesOak HC/FTGeneral CatalystMenlo VenturesThrive CapitalOpenAI VenturesDimension
Partners: Eli LillyPfizerNovartis
Investors: OpenAI Ventures
People: Joshua MeierCo-founder and CEOJack DentCo-founder

Spec

Chai-2 / Chai-3

Series C funding

$400M^R (reported)

Post-money valuation (Series C)

$3.8B^R (reported)

Time from Series C to paid deployments

<7 months^R (reported)