William Mack & Associates
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William Mack & Associates’s Biogen BIIB Stock Holding History

William Mack & Associates’s Portfolio BIIB Stock Details BIIB Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q3 		$13.1K Buy
+58
New +$12.3K ﹤0.01% 378

Other funds holding BIIB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.32T AUM 44.66% 1-Year Est. Return
BlackRock
BlackRock New York $6.79T AUM 37.06% 1-Year Est. Return
Primecap Management
Primecap Management Pasadena, California $161B AUM 86.05% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.76T AUM
State Street
State Street Boston, Massachusetts $3.44T AUM 36.12% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.21T AUM
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.92T AUM 36.1% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.96T AUM 27.49% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.84T AUM 33.86% 1-Year Est. Return
Invesco
Invesco Atlanta, Georgia $1.27T AUM 50.62% 1-Year Est. Return

William Mack & Associates's BIIB Position: Q3 2026 in Review

William Mack & Associates opened a new position in Biogen (BIIB) in Q3 2026: 58 shares worth $13.1K. The stake represents ﹤0.01% of the portfolio and ranks #378 among its holdings.

881 funds tracked by Wall St. Rank hold BIIB as of Q3 2026.

  • William Mack & Associates held 58 shares of Biogen worth $13.1K as of Q3 2026.
  • Biogen was a new William Mack & Associates position in Q3 2026.
  • Biogen made up ﹤0.01% of William Mack & Associates's portfolio in Q3 2026, its #378 holding.
  • 881 funds tracked by Wall St. Rank held Biogen as of Q3 2026.

Based on William Mack & Associates's 13F filing for Q3 2026, filed 27 Oct 2026.