Forty-two of the top-200 alpha managers filed new $ABT positions in Q1 2026, bringing total cohort holders to 58; zero added to existing stakes, zero trimmed, and just 2 exited. The initiation wave is the structural story here — not a gradual accumulation but a single-quarter step-change in breadth.
The largest new position belongs to Sectoral Asset Management Inc., which opened at 2.18% portfolio weight. Bradley Foster & Sargent INC initiated at 0.97%, and Bolthouse Investments, LLC entered at 0.74%. Among the two continuing top holders, Elefante Mark B held at 3.06% (down -0.45pp from 3.50%) and Bellevue Group AG sat at 2.81% (down -0.31pp from 3.13%) — both trimmed modestly but remained the cohort's largest concentrations.
Cohort-wide, the average position weight stands at 0.4%, with a range of 0.0% to 3.06%. The distribution is heavily right-skewed: the top two holders (Elefante and Bellevue) account for the bulk of aggregate weight, while the 42 initiators cluster below 1.0%. Wellington Management Group LLP, a prior holder, was essentially flat at 0.52% (+0.00pp).
Forty-two simultaneous initiations in one quarter — with no corresponding adds from existing holders — is an unusual configuration. The 14 flat holders and 2 exits suggest the prior cohort was not rotating out; the new entrants appear to be arriving independently rather than absorbing supply from departing positions.