a16z, Sequoia, and YC: 21 deals, a $515M down-exit, and three IPOs in the queue

In the roughly 90 days ending May 27, 2026, Andreessen Horowitz, Sequoia Capital, and Y Combinator touched 21 disclosed investment rounds totaling more than $7.5 billion across all co-investors. The single largest check — Anduril's $5 billion Series H, co-led by a16z — was larger than every other deal on this list combined. At the same time, one portfolio company sold at a steep step down from its 2022 peak, and three others are in active IPO processes. This digest covers every deal in that window, grouped by sector, and closes with what the exit pipeline means for the firms' LPs.

New investments

Bar chart showing the five largest rounds in the window — Anduril at $5B dwarfs all others — Largest rounds by deal size (a16z · Sequoia · YC-backed, Feb–May 2026). AI-generated illustration.

AI and infrastructure

Defense and AI infrastructure absorbed the heaviest capital this period.

Anduril — $5B Series H · May 13, 2026

What it does: Develops AI-driven autonomous weapons systems, drones, and military command platforms
Round: $5B Series H; valuation: $61B (up from $30.5B one year prior) 1
Lead investors: Thrive Capital and a16z (returning investors); total raised to date: $11.4B 2
Context: CEO Brian Schimpf reported 2025 revenue of $2.2B, up 100% year-over-year. Recent contracts include a U.S. Space Force "Golden Dome" missile defense system and a Netherlands Ministry of Defense deal. "When we founded Anduril in 2017, defense was not a category that attracted significant venture investment. That has changed meaningfully over the last several years," Schimpf said. 1

Decart — $300M · May 20, 2026

What it does: Builds real-time AI world models that generate interactive environments and live video transformations — used in simulation, robotics, gaming, and synthetic data
Round: $300M; valuation: ~$4B; total raised: $456M 3
Lead investor: Radical Ventures; Sequoia Capital, Benchmark, NVIDIA, and Andrej Karpathy also participated

Exa — $250M Series C · May 20, 2026

What it does: Provides a search engine and web-search API designed for AI applications — search, crawling, deep research, and web-content retrieval for developers
Round: $250M Series C; valuation: $2.2B; total raised: $357M 3
Lead investor: a16z

Parallel — $100M Series B · April 2026

What it does: API infrastructure that gives AI agents native access to execute web searches — founded by Parag Agrawal, formerly CEO of Twitter
Round: $100M Series B; valuation: $2B 4
Lead investor: Sequoia Capital; Kleiner Perkins, Index Ventures, and Khosla Ventures also participated

Standard Intelligence — $75M · April 2026

What it does: AI research lab developing general-intelligence architectures
Round: $75M 5
Investors: Sequoia Capital, Spark Capital

Braintrust — $80M · (window period)

What it does: AI agent platform for testing, monitoring, and deploying AI applications in enterprise environments
Round: $80M 6
Lead investor: ICONIQ; a16z also participated

Deeptune — $43M · (window period)

What it does: Builds simulated training environments that let AI models practice tasks — a data and knowledge infrastructure play
Round: $43M 6
Investors: a16z participated

Hilbert — $28M · April 2026

What it does: B2C growth infrastructure for real-time customer data analysis and marketing decisions
Round: $28M 5
Investor: a16z (sole disclosed investor)

Stilta — $10.5M · May 23, 2026

What it does: AI software for patent practitioners — prior art search, patent drafting, competitor monitoring, and portfolio valuation
Round: $10.5M; total raised: $11M 6
Investors: a16z and Y Combinator (co-invested)

Deals tracked

Combined disclosed capital

$7.5B+

Largest round (Anduril)

$5B

Confirmed exits

Sectors covered

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Fintech and banking

Mercury — $200M Series D · May 20, 2026

What it does: Banking accounts, corporate cards, spend management, and financial workflow tools for startups and tech companies
Round: $200M Series D; valuation: $5.2B (up from ~$3.2B) 3
Lead investor: TCV; a16z and Sequoia Capital both returned as co-investors — the only deal this window where two tracked firms participated together

Rowspace — $50M · (window period)

What it does: AI financial platform that helps investment funds process large document volumes and support investment decisions
Round: $50M early-stage 5
Lead investors: Sequoia Capital and Emergence Capital

ARQ — $70M · March 2026 (estimated)

What it does: Digital currency exchange platform serving Latin America at market rates
Round: $70M later-stage 7
Investors: Sequoia Capital, Founders Fund

Moment — $78M · May 23, 2026

What it does: AI operating system for wealth and asset managers — integrates trading, portfolio management, compliance, and analytics workflows
Round: $78M; total raised: $134M 6
Investors: a16z, Avra Capital, and Index Ventures

Healthcare

Commure — $70M · May 23, 2026

What it does: AI infrastructure for healthcare providers — ambient clinical documentation, revenue cycle automation, and clinical workflow tools
Round: $70M; total raised: $890.5M 6
Investors: Sequoia Capital, General Catalyst, Morgan Stanley, Kirkland & Ellis

Nourish — $100M · May 23, 2026

What it does: Telehealth platform connecting patients with registered dietitians for insurance-covered nutrition counseling — weight management, diabetes, gut health, eating disorders
Round: $100M; total raised: $213.1M 6
Investors: Y Combinator, Index Ventures, Thrive Capital, Atomico, Menlo Ventures

Blank Bio — $7.2M · May 23, 2026

What it does: RNA foundation model company helping pharma firms analyze disease progression and treatment response
Round: $7.2M 6
Investors: Y Combinator, Define Ventures

Industrial, aerospace, and manufacturing

Amca — $300M Series B · May 20, 2026

What it does: Aerospace manufacturing and supply chain platform that combines engineering certification, technical data development, and production in a single system
Round: $300M Series B; valuation: $1B+ (new unicorn); total raised: $376.5M 3
Lead investor: Caffeinated Capital; a16z, Lightspeed, Lux Capital, and Construct Capital also participated

SendCutSend — $110M · May 23, 2026

What it does: Online custom manufacturing service — laser cutting, waterjet cutting, CNC machining, bending, and finishing
Round: $110M (first external funding); founded 2018, Reno, Nevada 6
Investors: Sequoia Capital; Patrick Collison and John Collison (Stripe co-founders) and Paradigm also participated

Security and DevTools

Socket — $60M · May 23, 2026

What it does: Software supply chain security platform — detects malicious open-source packages, dependency risks, vulnerabilities, and zero-day supply chain attacks
Round: $60M; total raised: $125.1M 6
Investors: a16z, Thrive Capital, Capital One Ventures, Elad Gil

Consumer and enterprise tools

Status — $17M · May 23, 2026

What it does: AI social simulation and interactive narrative platform
Round: $17M; total raised: $34.6M 6
Investors: Y Combinator, General Catalyst, Abstract, Union Square Ventures

Leadbay — $4.3M · May 23, 2026

What it does: AI B2B sales lead discovery and qualification software
Round: $4.3M; total raised: $4.8M 6
Investors: Y Combinator, Alumni Ventures, Deel Ventures

Exits and IPO pipeline

Timeline diagram showing SpaceX, OpenAI, and Anthropic IPO progress across 2026 — 2026 IPO pipeline for a16z-backed portfolio companies. AI-generated illustration.

Brex → Capital One (completed April 7, 2026)

Corporate card and spend management platform Brex (YC W17 batch, a16z-backed) was acquired by Capital One for approximately $515 million in a cash-and-stock deal. 8 Brex had reached a $12.3 billion valuation in 2022, making the exit price a steep step down for anyone who invested at or near that peak. The deal closed the path to an independent IPO. Newcomer characterized the outcome as a letdown for late-stage investors but a workable return for early backers who got liquidity.

SpaceX — IPO filed May 20, 2026 (Nasdaq)

SpaceX publicly filed its IPO registration with the SEC on May 20, 2026, targeting a Nasdaq listing. 9 The company merged with xAI in February 2026 at a combined $1.25 trillion post-merger valuation; IPO projections range from $1.5T to $1.75T, with approximately 5% of equity on offer. The roadshow is scheduled to begin June 8, 2026. 2025 revenue was $18.6 billion, though the combined entity posted losses of $4.94 billion as xAI's AI infrastructure operations run at a deficit. a16z is a SpaceX investor, having led a $250 million round in 2015 and participated in subsequent rounds.

OpenAI — confidential IPO filing in preparation (targeting Q4 2026)

OpenAI is preparing to submit a confidential draft IPO prospectus to the SEC, working with Goldman Sachs and Morgan Stanley as lead underwriters. 10 Private investors currently value the company at over $850 billion; secondary trading on Forge Global puts it at approximately $900 billion. OpenAI reached an $800 billion valuation three years after ChatGPT's launch. The company is not expected to reach break-even until after 2028. a16z is an OpenAI investor.

Anthropic — in IPO pipeline, new fundraise ongoing

Anthropic is in active IPO discussions and conducting a new fundraising round. 11 Its current private valuation is $380 billion; secondary trading on Forge Global prices it at close to $1 trillion for IPO purposes. Revenue in Q1 2026 grew 80-fold year-over-year; the company is tracking toward a $45 billion annual run rate. Break-even is expected in 2028. Note: a16z's investor status in Anthropic was not independently verified from available sources; this item is included based on its significance within the exit pipeline.

What the IPO queue signals

Forbes estimates that SpaceX, OpenAI, and Anthropic together could deliver the largest VC payday in history — exceeding all VC returns combined from 2016 onward — if all three listings proceed. 11 The spread between Brex's $515M exit and SpaceX's $1.5T+ target illustrates how wide venture outcomes can run within a single firm's portfolio and a single quarter. For readers tracking capital allocation, the June 8 SpaceX roadshow start is the next concrete event to watch.

Cover image: AI-generated illustration.