BlackRock’s Spero Therapeutics SPRO Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2026
Q2
$1.31M Buy
594,404
+161,202
+37% +$422K ﹤0.01% 4268
2026
Q1
$1.01M Sell
433,202
-414
-0.1% -$983 ﹤0.01% 4346
2025
Q4
$1.01M Sell
433,616
-1,152
-0.3% -$2.67K ﹤0.01% 4299
2025
Q3
$817K Hold
434,768
﹤0.01% 4348
2025
Q2
$1.26M Sell
434,768
-47,314
-10% -$68.1K ﹤0.01% 4180
2025
Q1
$347K Sell
482,082
-3,270
-0.7% -$2.76K ﹤0.01% 4484
2024
Q4
$500K Buy
485,352
+532
+0.1% +$633 ﹤0.01% 4414
2024
Q3
$650K Buy
484,820
+1,418
+0.3% +$1.9K ﹤0.01% 4267
2024
Q2
$628K Buy
483,402
+6,506
+1% +$9.81K ﹤0.01% 4284
2024
Q1
$820K Sell
476,896
-3,703
-0.8% -$5.8K ﹤0.01% 4252
2023
Q4
$706K Sell
480,599
-1,210
-0.3% -$1.44K ﹤0.01% 4343
2023
Q3
$583K Sell
481,809
-41,995
-8% -$58.2K ﹤0.01% 4384
2023
Q2
$760K Buy
523,804
+33,991
+7% +$58.2K ﹤0.01% 4362
2023
Q1
$710K Buy
489,813
+1,730
+0.4% +$2.9K ﹤0.01% 4446
2022
Q4
$844K Sell
488,083
-204,055
-29% -$381K ﹤0.01% 4457
2022
Q3
$1.39M Buy
692,138
+1,385
+0.2% +$1.38K ﹤0.01% 4357
2022
Q2
$513K Sell
690,753
-1,103,328
-61% -$3.21M ﹤0.01% 4768
2022
Q1
$15.6M Sell
1,794,081
-4,696
-0.3% -$48.1K ﹤0.01% 3327
2021
Q4
$28.8M Sell
1,798,777
-3,751
-0.2% -$59.6K ﹤0.01% 3039
2021
Q3
$33.2M Buy
1,802,528
+23,706
+1% +$380K ﹤0.01% 2930
2021
Q2
$24.8M Buy
1,778,822
+2,226
+0.1% +$31.1K ﹤0.01% 3165
2021
Q1
$26.2M Buy
1,776,596
+44,996
+3% +$792K ﹤0.01% 3036
2020
Q4
$33.6M Buy
1,731,600
+654,438
+61% +$10.2M ﹤0.01% 2719
2020
Q3
$12M Buy
1,077,162
+126,906
+13% +$1.5M ﹤0.01% 3123
2020
Q2
$12.9M Buy
950,256
+69,025
+8% +$775K ﹤0.01% 3042
2020
Q1
$7.12M Buy
881,231
+125,966
+17% +$1.11M ﹤0.01% 3170
2019
Q4
$7.26M Buy
755,265
+76,316
+11% +$823K ﹤0.01% 3395
2019
Q3
$7.2M Buy
678,949
+22,171
+3% +$234K ﹤0.01% 3369
2019
Q2
$7.56M Buy
656,778
+235,691
+56% +$2.84M ﹤0.01% 3376
2019
Q1
$5.39M Buy
421,087
+27,457
+7% +$291K ﹤0.01% 3379
2018
Q4
$2.42M Buy
393,630
+21,161
+6% +$171K ﹤0.01% 3609
2018
Q3
$3.92M Buy
372,469
+30,470
+9% +$354K ﹤0.01% 3571
2018
Q2
$5.02M Buy
341,999
+89,698
+36% +$1.15M ﹤0.01% 3505
2018
Q1
$3.6M Buy
252,301
+11,427
+5% +$139K ﹤0.01% 3521
2017
Q4
$2.83M Buy
+240,874
New +$2.96M ﹤0.01% 3606

Other funds holding SPRO

BlackRock's SPRO Position: Q2 2026 in Review

BlackRock increased its Spero Therapeutics (SPRO) stake by 37% in Q2 2026, buying an estimated $422K and bringing the position to 594,404 shares worth $1.31M. The position accounts for ﹤0.01% of the portfolio, ranked #4268.

BlackRock first reported a position in SPRO in Q4 2017 and has held it in 35 quarters since. The position peaked at $33.6M in Q4 2020. 34 funds tracked by Wall St. Rank hold SPRO as of Q2 2026.

  • BlackRock held 594,404 shares of Spero Therapeutics worth $1.31M as of Q2 2026.
  • BlackRock bought 161,202 Spero Therapeutics shares in Q2 2026, an estimated $422K.
  • Spero Therapeutics made up ﹤0.01% of BlackRock's portfolio in Q2 2026, its #4268 holding.
  • BlackRock first reported a position in Spero Therapeutics in Q4 2017 and has held it in 35 quarters since.
  • BlackRock's Spero Therapeutics position peaked at $33.6M in Q4 2020.
  • 34 funds tracked by Wall St. Rank held Spero Therapeutics as of Q2 2026.

Based on BlackRock's 13F filing for Q2 2026, filed 7 Aug 2026.