Seres Therapeutics

MCRB

Market cap $50.5M

MCRB Hedge Fund Activity: Q1 2026 in Review

33 of the 8,128 institutional investors tracked by Wall St. Rank reported a position in Seres Therapeutics (MCRB) for Q1 2026, worth a combined $20.5M — down 44% from $36.4M a quarter earlier.

Sellers outnumbered buyers: 7 funds closed out of MCRB and 5 opened new positions — a net loss of 2 holders — while 8 trimmed existing stakes and 10 added.

The largest buyer was American Century Companies, adding an estimated $539K. The largest seller was Susquehanna International Group, cutting an estimated $874K.

• 33 institutional investors held Seres Therapeutics (MCRB) as of Q1 2026, down from 36 in Q4 2025.
• Funds reported $20.5M of Seres Therapeutics stock for Q1 2026, down 44% quarter-over-quarter.
• 5 funds opened new Seres Therapeutics positions in Q1 2026 and 7 closed out, a net change of -2 holders.
• The largest Seres Therapeutics buyer in Q1 2026 was American Century Companies, an estimated $539K added.
• The largest Seres Therapeutics seller in Q1 2026 was Susquehanna International Group, an estimated $874K sold.

Based on aggregated 13F filings for Q1 2026.