William Blair Investment Management
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William Blair Investment Management’s Repligen RGEN Stock Holding History

William Blair Investment Management’s Portfolio RGEN Stock Details RGEN Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$108M Buy
+788,571
New +$96.9M 0.32% 92
2024
Q2 		– Sell
-634,990
Closed -$117M – 443
2024
Q1 		$117M Sell
634,990
-270,770
-30% -$51.6M 0.3% 98
2023
Q4 		$163M Sell
905,760
-41,133
-4% -$6.4M 0.47% 72
2023
Q3 		$151M Buy
946,893
+1,024
+0.1% +$167K 0.5% 67
2023
Q2 		$134M Buy
945,869
+34,501
+4% +$5.53M 0.43% 80
2023
Q1 		$153M Buy
911,368
+237,796
+35% +$42.4M 0.53% 57
2022
Q4 		$114M Buy
673,572
+126,188
+23% +$22.9M 0.44% 81
2022
Q3 		$102M Sell
547,384
-185,702
-25% -$39.2M 0.4% 85
2022
Q2 		$119M Buy
+733,086
New +$116M 0.44% 80
2018
Q4 		– Sell
-1,363,109
Closed -$75.6M – 427
2018
Q3 		$75.6M Sell
1,363,109
-443,195
-25% -$22.8M 0.26% 112
2018
Q2 		$85M Sell
1,806,304
-399
-0% -$16.4K 0.32% 104
2018
Q1 		$65.4M Buy
1,806,703
+4,134
+0.2% +$145K 0.25% 121
2017
Q4 		$65.4M Buy
1,802,569
+742,634
+70% +$26.9M 0.25% 121
2017
Q3 		$40.6M Buy
1,059,935
+959
+0.1% +$40.2K 0.15% 160
2017
Q2 		$43.9M Buy
1,058,976
+352,045
+50% +$13.4M 0.16% 157
2017
Q1 		$24.9M Buy
706,931
+30,198
+4% +$956K 0.09% 199
2016
Q4 		$20.9M Buy
676,733
+5,820
+0.9% +$180K 0.08% 227
2016
Q3 		$20.3M Sell
670,913
-126,031
-16% -$3.8M 0.08% 220
2016
Q2 		$21.8M Buy
796,944
+511,296
+179% +$13.1M 0.09% 202
2016
Q1 		$7.66M Buy
285,648
+124,755
+78% +$3.05M 0.03% 315
2015
Q4 		$4.55M Sell
160,893
-5,112
-3% -$147K 0.02% 359
2015
Q3 		$4.62M Buy
+166,005
New +$6M 0.01% 803

Other funds holding RGEN

BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
UCFA
United Capital Financial Advisors Irving, Texas $18.2B AUM 22.02% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
MC
Maverick Capital Dallas, Texas $11.3B AUM 76.6% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
T. Rowe Price Associates
T. Rowe Price Associates Baltimore, Maryland $999B AUM 46.22% 1-Year Est. Return
Massachusetts Financial Services
Massachusetts Financial Services Boston, Massachusetts $315B AUM 27.84% 1-Year Est. Return
WA
Wasatch Advisors Salt Lake City, Utah $15.3B AUM 25.06% 1-Year Est. Return

William Blair Investment Management's RGEN Position: Q2 2026 in Review

William Blair Investment Management opened a new position in Repligen (RGEN) in Q2 2026: 788,571 shares worth $108M. The stake represents 0.32% of the portfolio and ranks #92 among its holdings. This is a return to the name: William Blair Investment Management previously reported a position in RGEN as recently as Q1 2024.

William Blair Investment Management first reported a position in RGEN in Q3 2015 and has held it in 22 quarters since. The position peaked at $163M in Q4 2023. 480 funds tracked by Wall St. Rank hold RGEN as of Q2 2026.

  • William Blair Investment Management held 788,571 shares of Repligen worth $108M as of Q2 2026.
  • Repligen was a new William Blair Investment Management position in Q2 2026.
  • Repligen made up 0.32% of William Blair Investment Management's portfolio in Q2 2026, its #92 holding.
  • William Blair Investment Management first reported a position in Repligen in Q3 2015 and has held it in 22 quarters since.
  • William Blair Investment Management's Repligen position peaked at $163M in Q4 2023.
  • 480 funds tracked by Wall St. Rank held Repligen as of Q2 2026.

Based on William Blair Investment Management's 13F filing for Q2 2026, filed 12 Aug 2026.