SERA PROGNOSTICS, INC.

## Signal Note: Baker Bros. Initiates Large Position in Sera Prognostics (SERA) **Note: The reported position value of ~$16.2B appears to be a data error — SERA's entire market cap is roughly $150-200M; the 5.5M share count likely represents a meaningful stake but at a realistic value closer to ~$15-20M.** That said, Baker Bros. taking a new concentrated position in SERA is noteworthy given their track record of high-conviction biotech bets. Sera's core asset is the PreTRM test, a blood-based biomarker assay for predicting preterm birth risk, with the key commercial catalyst being expanded payer coverage and potential CMS reimbursement decisions that could unlock a large maternal health market. Baker's entry suggests they see an inflection point in commercialization or possible strategic value, consistent with their pattern of building