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Team Portfolio Raise Champions Essays

F4/Altimeter/Activity

Altimeter Activity

Every public signal F4 has attached to this firm, with sources and cross-entity links.

Types

Time range

Investment

Co-led Baseten's $1.5B Series F round alongside Conviction and Spark Capital for AI inference infrastructure.

Baseten

Baseten Altimeter

businesswire.comJUN 22, 2026

JUN 22, 2026

Altimeter | Activity | F4

Investment

Participated as an existing investor in Sigma's $80M Series E round, valuing the company at $3B.

Sigma Computing

Sigma Computing Altimeter

siliconangle.comMAY 18, 2026

MAY 18, 2026

Exit

Portfolio company Cerebras Systems raised $5.5B in a ~$40B IPO, the largest tech IPO of 2026 so far.

Cerebras

Cerebras Altimeter

techcrunch.comMAY 14, 2026

MAY 14, 2026

3 investments· FEB 2026 – MAR 2026Show all

Investment

Participated in OpenAI's $122B funding round at $852B valuation, investing approximately $250M.

OpenAI

OpenAI Altimeter

openai.comMAR 25, 2026

MAR 25, 2026

Investment

Participated in Anthropic's $30B Series G round at a $380B post-money valuation.

Anthropic

Anthropic Altimeter

techcrunch.comFEB 12, 2026

FEB 12, 2026

Investment

Participated in Cerebras Systems' $1B Series H round at $23B valuation, led by Tiger Global.

Cerebras Systems

Cerebras Systems Altimeter

cerebras.aiFEB 2026

FEB 2026

Exit

Portfolio company Groq was acquired by NVIDIA for $20B.

Groq

intuitionlabs.aiDEC 24, 2025

DEC 24, 2025

News

Executed strategic portfolio simplification in Q4 2025, eliminating China-related and cyclical exposure, redeploying toward higher-conviction infrastructure assets.

Q4 2025 portfolio rebalancing toward AI infrastructure

gainify.ioDEC 2025

DEC 2025

Exit

Completed exit from Alibaba Group ($157.83M), withdrawing from China-centric platforms amid persistent policy uncertainty.

Alibaba

Alibaba Altimeter

gainify.ioDEC 2025

DEC 2025

Exit

Exited Arm Holdings position ($159.66M sale), reducing conviction in semiconductor IP licensing relative to AI infrastructure.

Arm Holdings

Arm Holdings Altimeter

gainify.ioDEC 2025

DEC 2025