William Blair & Company
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William Blair & Company’s iShares Biotechnology ETF IBB Stock Holding History

William Blair & Company’s Portfolio IBB Stock Details IBB Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$2.5M Buy
14,777
+3,101
+27% +$530K 0.01% 668
2025
Q4 		$1.97M Sell
11,676
-166
-1% -$27K 0.01% 749
2025
Q3 		$1.71M Sell
11,842
-2,440
-17% -$333K ﹤0.01% 771
2025
Q2 		$1.81M Sell
14,282
-8,799
-38% -$1.08M 0.01% 743
2025
Q1 		$2.95M Sell
23,081
-686
-3% -$93K 0.01% 620
2024
Q4 		$3.14M Sell
23,767
-40,132
-63% -$5.64M 0.01% 611
2024
Q3 		$9.3M Buy
63,899
+16,755
+36% +$2.42M 0.03% 355
2024
Q2 		$6.47M Sell
47,144
-3,603
-7% -$481K 0.02% 411
2024
Q1 		$6.96M Buy
50,747
+5,608
+12% +$766K 0.02% 395
2023
Q4 		$6.13M Sell
45,139
-608
-1% -$74.2K 0.02% 415
2023
Q3 		$5.59M Sell
45,747
-218
-0.5% -$27.7K 0.02% 413
2023
Q2 		$5.84M Buy
45,965
+680
+2% +$88.3K 0.02% 410
2023
Q1 		$5.85M Buy
45,285
+6,075
+15% +$795K 0.02% 407
2022
Q4 		$5.15M Buy
39,210
+18,824
+92% +$2.43M 0.02% 423
2022
Q3 		$2.38M Buy
20,386
+2,660
+15% +$330K 0.01% 574
2022
Q2 		$2.08M Sell
17,726
-991
-5% -$118K 0.01% 629
2022
Q1 		$2.44M Buy
18,717
+1,659
+10% +$216K 0.01% 651
2021
Q4 		$2.6M Buy
17,058
+492
+3% +$76.2K 0.01% 647
2021
Q3 		$2.68M Buy
16,566
+19
+0.1% +$3.2K 0.01% 622
2021
Q2 		$2.71M Sell
16,547
-6,817
-29% -$1.05M 0.01% 607
2021
Q1 		$3.52M Buy
23,364
+756
+3% +$120K 0.01% 537
2020
Q4 		$3.42M Sell
22,608
-739
-3% -$106K 0.01% 516
2020
Q3 		$3.16M Buy
23,347
+4,486
+24% +$609K 0.01% 488
2020
Q2 		$2.58M Buy
18,861
+656
+4% +$83.6K 0.01% 502
2020
Q1 		$1.96M Buy
18,205
+3,334
+22% +$384K 0.01% 515
2019
Q4 		$1.79M Sell
14,871
-564
-4% -$62.9K 0.01% 632
2019
Q3 		$1.54M Sell
15,435
-25,431
-62% -$2.66M 0.01% 645
2019
Q2 		$4.46M Sell
40,866
-4,037
-9% -$429K 0.03% 399
2019
Q1 		$5.02M Sell
44,903
-3,628
-7% -$398K 0.03% 365
2018
Q4 		$4.68M Sell
48,531
-969
-2% -$103K 0.03% 343
2018
Q3 		$6.04M Sell
49,500
-6,449
-12% -$759K 0.04% 337
2018
Q2 		$6.14M Buy
55,949
+8,565
+18% +$916K 0.04% 312
2018
Q1 		$5.06M Sell
47,384
-29,523
-38% -$3.27M 0.04% 343
2017
Q4 		$8.21M Buy
76,907
+38,615
+101% +$4.13M 0.06% 266
2017
Q3 		$4.26M Buy
38,292
+264
+0.7% +$28.2K 0.03% 375
2017
Q2 		$3.93M Buy
38,028
+2,550
+7% +$251K 0.03% 400
2017
Q1 		$3.51M Buy
35,478
+15
+0% +$1.44K 0.03% 402
2016
Q4 		$3.14M Buy
35,463
+13,872
+64% +$1.26M 0.03% 394
2016
Q3 		$2.08M Sell
21,591
-11,340
-34% -$1.08M 0.02% 487
2016
Q2 		$2.83M Buy
32,931
+14,628
+80% +$1.31M 0.03% 400
2016
Q1 		$1.59M Buy
18,303
+249
+1% +$22.3K 0.02% 503
2015
Q4 		$2.04M Buy
18,054
+693
+4% +$75.2K 0.02% 468
2015
Q3 		$1.75M Buy
17,361
+828
+5% +$99.3K 0.02% 568
2015
Q2 		$2.03M Buy
16,533
+375
+2% +$44.9K ﹤0.01% 1345
2015
Q1 		$1.85M Buy
16,158
+357
+2% +$39.4K ﹤0.01% 1342
2014
Q4 		$1.6M Sell
15,801
-1,440
-8% -$140K ﹤0.01% 1344
2014
Q3 		$1.57M Sell
17,241
-5,784
-25% -$508K ﹤0.01% 1338
2014
Q2 		$1.97M Sell
23,025
-1,125
-5% -$88.6K ﹤0.01% 1240
2014
Q1 		$1.9M Sell
24,150
-9,120
-27% -$760K ﹤0.01% 1220
2013
Q4 		$2.52M Sell
33,270
-38,115
-53% -$2.7M ﹤0.01% 1109
2013
Q3 		$4.99M Buy
71,385
+10,695
+18% +$701K 0.01% 897
2013
Q2 		$3.52M Buy
+60,690
New +$3.51M 0.01% 944

Other funds holding IBB

Bank of America
Bank of America Charlotte, North Carolina $1.37T AUM 24.88% 1-Year Est. Return
Citigroup
Citigroup New York $235B AUM 32.99% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return
BNP Paribas Financial Markets
BNP Paribas Financial Markets Paris, France $206B AUM 31.61% 1-Year Est. Return
JP Morgan Chase
JP Morgan Chase New York $1.56T AUM 27.86% 1-Year Est. Return
Goldman Sachs
Goldman Sachs New York $871B AUM 31.28% 1-Year Est. Return
Envestnet Asset Management
Envestnet Asset Management Chicago, Illinois $374B AUM 17.66% 1-Year Est. Return
Raymond James Financial
Raymond James Financial St Petersburg, Florida $324B AUM 22.36% 1-Year Est. Return
CB
Commerce Bank Kansas City, Missouri $20.7B AUM 23.76% 1-Year Est. Return
Wells Fargo
Wells Fargo San Francisco, California $530B AUM 22.01% 1-Year Est. Return

William Blair & Company's IBB Position: Q1 2026 in Review

William Blair & Company increased its iShares Biotechnology ETF (IBB) stake by 27% in Q1 2026, buying an estimated $530K and bringing the position to 14,777 shares worth $2.5M. The position accounts for 0.01% of the portfolio, ranked #668.

William Blair & Company first reported a position in IBB in Q2 2013 and has held it in 52 quarters since. The position peaked at $9.3M in Q3 2024. 919 funds tracked by Wall St. Rank hold IBB as of Q1 2026.

  • William Blair & Company held 14,777 shares of iShares Biotechnology ETF worth $2.5M as of Q1 2026.
  • William Blair & Company bought 3,101 iShares Biotechnology ETF shares in Q1 2026, an estimated $530K.
  • iShares Biotechnology ETF made up 0.01% of William Blair & Company's portfolio in Q1 2026, its #668 holding.
  • William Blair & Company first reported a position in iShares Biotechnology ETF in Q2 2013 and has held it in 52 quarters since.
  • William Blair & Company's iShares Biotechnology ETF position peaked at $9.3M in Q3 2024.
  • 919 funds tracked by Wall St. Rank held iShares Biotechnology ETF as of Q1 2026.

Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.