Addition

Addition founder Lee Fixel and wife Lauren co-founded the Lauren and Lee Fixel Family Foundation. In 2025, the foundation supported the launch of the Food and Agriculture Research Mission (FARM) at Washington University in St. Louis—an initiative to address challenges in agricultural production, food distribution, and access to nutritious foods. Addition's portfolio also includes Zap Energy, a clean energy company developing shear-flow-stabilized Z-pinch fusion technology for commercial power generation without superconducting magnets.

Addition portfolio company Vacasa, the vacation rental management platform, conducted significant layoffs in 2023-2024. In January 2023, Vacasa eliminated approximately 1,300 positions (17% of workforce) across local operations and central teams. In February 2024, Vacasa approved a second workforce reduction eliminating 320 additional positions (5% of workforce). Addition, founded by former Tiger Global partner Lee Fixel, is known for growth-stage investments but several portfolio companies faced headcount reductions during the 2022-2024 tech downturn.

Addition led Hugging Face's $40M Series B funding round, backing the leading open-source AI model hub before the generative AI boom. Founder Lee Fixel recognized Hugging Face's mission to "revolutionize machine learning by providing natural language processing technologies in open source mode." Addition continued investing through the Series C. The firm's portfolio emphasis on open-source AI infrastructure aligns with responsible AI development through transparency and community access.