American Century Companies’s Ionis Pharmaceuticals IONS Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2026
Q1
$125M Buy
1,663,803
+46,697
+3% +$3.69M 0.06% 337
2025
Q4
$128M Buy
1,617,106
+244,881
+18% +$18.4M 0.06% 325
2025
Q3
$89.8M Buy
1,372,225
+899,476
+190% +$43.9M 0.05% 454
2025
Q2
$18.7M Buy
472,749
+355,981
+305% +$11.6M 0.01% 1126
2025
Q1
$3.52M Buy
+116,768
New +$3.82M ﹤0.01% 1748
2024
Q4
Sell
-6,293
Closed -$252K 2918
2024
Q3
$252K Sell
6,293
-7,148
-53% -$333K ﹤0.01% 2703
2024
Q2
$641K Buy
13,441
+63
+0.5% +$2.58K ﹤0.01% 2350
2024
Q1
$580K Buy
13,378
+162
+1% +$7.72K ﹤0.01% 2383
2023
Q4
$669K Buy
13,216
+234
+2% +$11.2K ﹤0.01% 2250
2023
Q3
$589K Buy
12,982
+375
+3% +$15.5K ﹤0.01% 2206
2023
Q2
$517K Sell
12,607
-556
-4% -$21.4K ﹤0.01% 2204
2023
Q1
$470K Sell
13,163
-17,709
-57% -$665K ﹤0.01% 2149
2022
Q4
$1.17M Buy
30,872
+20,793
+206% +$875K ﹤0.01% 1742
2022
Q3
$446K Buy
10,079
+2,724
+37% +$115K ﹤0.01% 1995
2022
Q2
$272K Buy
7,355
+1,761
+31% +$66.4K ﹤0.01% 2076
2022
Q1
$207K Buy
+5,594
New +$183K ﹤0.01% 2170
2021
Q4
Sell
-199,346
Closed -$6.69M 2345
2021
Q3
$6.69M Sell
199,346
-26,834
-12% -$1.01M ﹤0.01% 953
2021
Q2
$9.02M Sell
226,180
-716,498
-76% -$28.1M 0.01% 847
2021
Q1
$42.4M Sell
942,678
-301,852
-24% -$16.8M 0.03% 475
2020
Q4
$70.4M Sell
1,244,530
-91,184
-7% -$4.54M 0.05% 326
2020
Q3
$63.4M Sell
1,335,714
-112,168
-8% -$6.23M 0.06% 314
2020
Q2
$85.4M Buy
1,447,882
+40,254
+3% +$2.24M 0.08% 258
2020
Q1
$66.6M Sell
1,407,628
-8,657
-0.6% -$483K 0.08% 260
2019
Q4
$85.6M Buy
1,416,285
+44,471
+3% +$2.65M 0.08% 264
2019
Q3
$82.2M Buy
1,371,814
+2,338
+0.2% +$152K 0.08% 268
2019
Q2
$88M Buy
1,369,476
+69,096
+5% +$4.88M 0.09% 270
2019
Q1
$106M Sell
1,300,380
-304,594
-19% -$19.6M 0.11% 247
2018
Q4
$86.8M Buy
1,604,974
+414,255
+35% +$21.1M 0.1% 254
2018
Q3
$61.4M Buy
1,190,719
+5,537
+0.5% +$260K 0.06% 325
2018
Q2
$49.4M Buy
1,185,182
+6,266
+0.5% +$278K 0.05% 358
2018
Q1
$52M Sell
1,178,916
-2,193
-0.2% -$111K 0.05% 351
2017
Q4
$59.4M Buy
1,181,109
+36,583
+3% +$2.01M 0.06% 347
2017
Q3
$58M Buy
1,144,526
+284,266
+33% +$14.9M 0.06% 351
2017
Q2
$43.8M Sell
860,260
-1,697
-0.2% -$79K 0.05% 391
2017
Q1
$34.7M Buy
861,957
+145,850
+20% +$6.55M 0.04% 429
2016
Q4
$34.3M Buy
716,107
+80,912
+13% +$3.2M 0.04% 439
2016
Q3
$23.3M Sell
635,195
-1,610
-0.3% -$50.4K 0.03% 503
2016
Q2
$14.8M Buy
636,805
+76,987
+14% +$2.48M 0.02% 584
2016
Q1
$22.7M Buy
559,818
+49,565
+10% +$2.01M 0.03% 488
2015
Q4
$31.6M Buy
510,253
+2,838
+0.6% +$153K 0.04% 443
2015
Q3
$20.5M Buy
507,415
+29,108
+6% +$1.51M 0.03% 507
2015
Q2
$27.5M Sell
478,307
-16,076
-3% -$1.02M 0.03% 492
2015
Q1
$31.5M Sell
494,383
-6,083
-1% -$413K 0.04% 460
2014
Q4
$30.9M Buy
500,466
+36,629
+8% +$1.81M 0.03% 465
2014
Q3
$18M Sell
463,837
-69,779
-13% -$2.47M 0.02% 547
2014
Q2
$18.4M Sell
533,616
-586,775
-52% -$18.5M 0.02% 556
2014
Q1
$48.4M Buy
1,120,391
+993,171
+781% +$48.1M 0.06% 372
2013
Q4
$5.07M Buy
127,220
+47,428
+59% +$1.69M 0.01% 896
2013
Q3
$3M Sell
79,792
-14,188
-15% -$424K ﹤0.01% 1020
2013
Q2
$2.52M Buy
+93,980
New +$2M ﹤0.01% 1032

Other funds holding IONS

American Century Companies's IONS Position: Q1 2026 in Review

American Century Companies increased its Ionis Pharmaceuticals (IONS) stake by 2.9% in Q1 2026, buying an estimated $3.69M and bringing the position to 1,663,803 shares worth $125M. The position accounts for 0.06% of the portfolio, ranked #337.

American Century Companies first reported a position in IONS in Q2 2013 and has held it in 50 quarters since. The position peaked at $128M in Q4 2025. 493 funds tracked by Wall St. Rank hold IONS as of Q1 2026.

  • American Century Companies held 1,663,803 shares of Ionis Pharmaceuticals worth $125M as of Q1 2026.
  • American Century Companies bought 46,697 Ionis Pharmaceuticals shares in Q1 2026, an estimated $3.69M.
  • Ionis Pharmaceuticals made up 0.06% of American Century Companies's portfolio in Q1 2026, its #337 holding.
  • American Century Companies first reported a position in Ionis Pharmaceuticals in Q2 2013 and has held it in 50 quarters since.
  • American Century Companies's Ionis Pharmaceuticals position peaked at $128M in Q4 2025.
  • 493 funds tracked by Wall St. Rank held Ionis Pharmaceuticals as of Q1 2026.

Based on American Century Companies's 13F filing for Q1 2026, filed 15 May 2026.