William Blair & Company
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William Blair & Company’s argenx ARGX Stock Holding History

William Blair & Company’s Portfolio ARGX Stock Details ARGX Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$25.7M Buy
27,666
+5,259
+23% +$4.34M 0.07% 221
2026
Q1 		$16.4M Sell
22,407
-3,933
-15% -$3.08M 0.05% 269
2025
Q4 		$22.2M Buy
26,340
+23,957
+1,005% +$20.5M 0.06% 226
2025
Q3 		$1.76M Buy
2,383
+73
+3% +$48.1K ﹤0.01% 762
2025
Q2 		$1.27M Buy
2,310
+231
+11% +$134K ﹤0.01% 824
2025
Q1 		$1.23M Buy
2,079
+1,165
+127% +$735K ﹤0.01% 828
2024
Q4 		$562K Sell
914
-6
-0.7% -$3.52K ﹤0.01% 1065
2024
Q3 		$499K Buy
920
+9
+1% +$4.55K ﹤0.01% 1114
2024
Q2 		$392K Sell
911
-534
-37% -$204K ﹤0.01% 1176
2024
Q1 		$569K Sell
1,445
-695
-32% -$269K ﹤0.01% 1049
2023
Q4 		$814K Buy
2,140
+261
+14% +$122K ﹤0.01% 925
2023
Q3 		$924K Buy
1,879
+159
+9% +$77.8K ﹤0.01% 870
2023
Q2 		$670K Buy
1,720
+675
+65% +$265K ﹤0.01% 971
2023
Q1 		$389K Sell
1,045
-375
-26% -$139K ﹤0.01% 1136
2022
Q4 		$538K Sell
1,420
-158
-10% -$59.1K ﹤0.01% 1023
2022
Q3 		$557K Buy
1,578
+3
+0.2% +$1.11K ﹤0.01% 1002
2022
Q2 		$597K Hold
1,575
– – ﹤0.01% 1007
2022
Q1 		$497K Sell
1,575
-12
-0.8% -$3.49K ﹤0.01% 1157
2021
Q4 		$556K Buy
1,587
+12
+0.8% +$3.65K ﹤0.01% 1173
2021
Q3 		$476K Hold
1,575
– – ﹤0.01% 1169
2021
Q2 		$474K Hold
1,575
– – ﹤0.01% 1161
2021
Q1 		$434K Hold
1,575
– – ﹤0.01% 1181
2020
Q4 		$463K Hold
1,575
– – ﹤0.01% 1105
2020
Q3 		$413K Hold
1,575
– – ﹤0.01% 1030
2020
Q2 		$355K Hold
1,575
– – ﹤0.01% 1031
2020
Q1 		$207K Hold
1,575
– – ﹤0.01% 1154
2019
Q4 		$253K Buy
+1,575
New +$213K ﹤0.01% 1231
2019
Q3 		– Sell
-2,200
Closed -$311K – 1692
2019
Q2 		$311K Hold
2,200
– – ﹤0.01% 1141
2019
Q1 		$275K Buy
+2,200
New +$259K ﹤0.01% 1176

Other funds holding ARGX

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
T. Rowe Price Associates
T. Rowe Price Associates Baltimore, Maryland $999B AUM 46.22% 1-Year Est. Return
JT
Jupiter Topco New York $245B AUM
Capital World Investors
Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return
Artisan Partners
Artisan Partners Milwaukee, Wisconsin $63.1B AUM 35.51% 1-Year Est. Return
ACA
Avoro Capital Advisors New York $11.1B AUM 207.82% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
RI
RTW Investments New York $11.7B AUM 174.13% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

William Blair & Company's ARGX Position: Q2 2026 in Review

William Blair & Company increased its argenx (ARGX) stake by 23% in Q2 2026, buying an estimated $4.34M and bringing the position to 27,666 shares worth $25.7M. The position accounts for 0.07% of the portfolio, ranked #221.

William Blair & Company first reported a position in ARGX in Q1 2019 and has held it in 29 quarters since. 507 funds tracked by Wall St. Rank hold ARGX as of Q2 2026.

  • William Blair & Company held 27,666 shares of argenx worth $25.7M as of Q2 2026.
  • William Blair & Company bought 5,259 argenx shares in Q2 2026, an estimated $4.34M.
  • argenx made up 0.07% of William Blair & Company's portfolio in Q2 2026, its #221 holding.
  • William Blair & Company first reported a position in argenx in Q1 2019 and has held it in 29 quarters since.
  • 507 funds tracked by Wall St. Rank held argenx as of Q2 2026.

Based on William Blair & Company's 13F filing for Q2 2026, filed 11 Aug 2026.