Logos Capital

Arsani William, the firm's founder and managing partner, is the sole portfolio manager. He is a medical doctor by training and made the call to leave a prior healthcare investing role to launch Logos in 2019. The structure is intentionally flat — there is no investment committee or multi-PM risk-book system. William's clinical judgment and proprietary bioinformatics pipeline drive every position the fund takes.

Logos runs a long-biased public-equity portfolio concentrated in biotechnology and precision-medicine companies. The firm targets small- to mid-cap names with near-term binary catalysts: Phase III trial results, FDA panel votes, or label-expansion decisions. Sector concentration spans oncology, rare disease, immunology, and AI-enabled drug discovery platforms. It does not appear to run a short book of meaningful size.

The structural differentiator is that the founder and sole decision-maker is a physician who actively interprets clinical-trial data himself, rather than delegating to a team of PhD analysts feeding a committee. Most large biotech funds — Baker Bros, Perceptive, RTW — deploy teams of scientists and distribute risk across multiple sub-portfolios. Logos bets that one clinician-investor, reading the same data as everyone else, can reach a contrarian conclusion faster. That is the entire strategy.