NS Partners
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NS Partners’s Biogen BIIB Stock Holding History

NS Partners’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 		$804K Buy
+3,558
New +$755K 0.03% 139
2019
Q1 		– Sell
-8,804
Closed -$2.65M – 111
2018
Q4 		$2.65M Sell
8,804
-75
-0.8% -$23.9K 0.28% 82
2018
Q3 		$3.14M Sell
8,879
-24
-0.3% -$8.26K 0.3% 82
2018
Q2 		$2.58M Hold
8,903
– – 0.27% 84
2018
Q1 		$2.44M Sell
8,903
-291
-3% -$90.3K 0.26% 88
2017
Q4 		$2.93M Buy
9,194
+165
+2% +$52.9K 0.32% 81
2017
Q3 		$2.83M Buy
9,029
+3,086
+52% +$914K 0.34% 81
2017
Q2 		$1.61M Buy
5,943
+368
+7% +$97.3K 0.21% 83
2017
Q1 		$1.52M Sell
5,575
-10,642
-66% -$3.01M 0.22% 89
2016
Q4 		$4.6M Buy
16,217
+111
+0.7% +$32.9K 0.72% 63
2016
Q3 		$5.04M Buy
16,106
+35
+0.2% +$10.4K 0.82% 53
2016
Q2 		$3.89M Buy
16,071
+4,691
+41% +$1.24M 0.66% 66
2016
Q1 		$2.96M Buy
11,380
+235
+2% +$62.1K 0.53% 71
2015
Q4 		$3.41M Sell
11,145
-587
-5% -$169K 0.61% 71
2015
Q3 		$3.42M Sell
11,732
-247
-2% -$81.6K 0.6% 72
2015
Q2 		$4.84M Buy
+11,979
New +$4.81M 0.77% 59

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

NS Partners's BIIB Position: Q3 2026 in Review

NS Partners opened a new position in Biogen (BIIB) in Q3 2026: 3,558 shares worth $804K. The stake represents 0.03% of the portfolio and ranks #139 among its holdings. This is a return to the name: NS Partners previously reported a position in BIIB as recently as Q4 2018.

NS Partners first reported a position in BIIB in Q2 2015 and has held it in 16 quarters since. The position peaked at $5.04M in Q3 2016. 881 funds tracked by Wall St. Rank hold BIIB as of Q3 2026.

  • NS Partners held 3,558 shares of Biogen worth $804K as of Q3 2026.
  • Biogen was a new NS Partners position in Q3 2026.
  • Biogen made up 0.03% of NS Partners's portfolio in Q3 2026, its #139 holding.
  • NS Partners first reported a position in Biogen in Q2 2015 and has held it in 16 quarters since.
  • NS Partners's Biogen position peaked at $5.04M in Q3 2016.
  • 881 funds tracked by Wall St. Rank held Biogen as of Q3 2026.

Based on NS Partners's 13F filing for Q3 2026, filed 10 Nov 2026.