William Blair & Company’s Costco COST Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q1 | $519M | Buy |
521,277
+95
| +0% | +$92.6K | 1.49% | 12 |
|
|
2025
Q4 | $449M | Sell |
521,182
-30,376
| -6% | -$27.5M | 1.21% | 13 |
|
|
2025
Q3 | $511M | Sell |
551,558
-428
| -0.1% | -$410K | 1.36% | 12 |
|
|
2025
Q2 | $546M | Buy |
551,986
+3,087
| +0.6% | +$3.07M | 1.52% | 10 |
|
|
2025
Q1 | $519M | Sell |
548,899
-39,157
| -7% | -$38.2M | 1.57% | 8 |
|
|
2024
Q4 | $539M | Sell |
588,056
-402
| -0.1% | -$373K | 1.57% | 9 |
|
|
2024
Q3 | $522M | Buy |
588,458
+19,805
| +3% | +$17.2M | 1.53% | 8 |
|
|
2024
Q2 | $483M | Sell |
568,653
-1,110
| -0.2% | -$866K | 1.49% | 11 |
|
|
2024
Q1 | $417M | Sell |
569,763
-3,823
| -0.7% | -$2.73M | 1.31% | 13 |
|
|
2023
Q4 | $379M | Buy |
573,586
+10,759
| +2% | +$6.38M | 1.29% | 14 |
|
|
2023
Q3 | $318M | Buy |
562,827
+7,548
| +1% | +$4.17M | 1.22% | 15 |
|
|
2023
Q2 | $299M | Buy |
555,279
+55,929
| +11% | +$28.3M | 1.1% | 16 |
|
|
2023
Q1 | $248M | Buy |
499,350
+25,044
| +5% | +$12.3M | 0.99% | 20 |
|
|
2022
Q4 | $217M | Buy |
474,306
+3,485
| +0.7% | +$1.7M | 0.94% | 19 |
|
|
2022
Q3 | $222M | Buy |
470,821
+12,091
| +3% | +$6.29M | 1.02% | 16 |
|
|
2022
Q2 | $220M | Buy |
458,730
+10,539
| +2% | +$5.35M | 0.98% | 15 |
|
|
2022
Q1 | $258M | Buy |
448,191
+4,179
| +0.9% | +$2.19M | 0.9% | 17 |
|
|
2021
Q4 | $252M | Buy |
444,012
+1,083
| +0.2% | +$555K | 0.79% | 29 |
|
|
2021
Q3 | $199M | Sell |
442,929
-2,237
| -0.5% | -$983K | 0.68% | 30 |
|
|
2021
Q2 | $176M | Buy |
445,166
+14,392
| +3% | +$5.44M | 0.61% | 39 |
|
|
2021
Q1 | $152M | Buy |
430,774
+41,439
| +11% | +$14.4M | 0.57% | 39 |
|
|
2020
Q4 | $147M | Buy |
389,335
+4,795
| +1% | +$1.79M | 0.54% | 41 |
|
|
2020
Q3 | $137M | Buy |
384,540
+37,508
| +11% | +$12.6M | 0.58% | 38 |
|
|
2020
Q2 | $105M | Buy |
347,032
+9,268
| +3% | +$2.82M | 0.5% | 42 |
|
|
2020
Q1 | $96.3M | Buy |
337,764
+7,237
| +2% | +$2.2M | 0.6% | 40 |
|
|
2019
Q4 | $97.1M | Sell |
330,527
-2,960
| -0.9% | -$880K | 0.5% | 45 |
|
|
2019
Q3 | $96.1M | Buy |
333,487
+1,001
| +0.3% | +$282K | 0.55% | 43 |
|
|
2019
Q2 | $87.9M | Buy |
332,486
+29,895
| +10% | +$7.45M | 0.5% | 47 |
|
|
2019
Q1 | $73.3M | Buy |
302,591
+11,124
| +4% | +$2.43M | 0.45% | 58 |
|
|
2018
Q4 | $59.4M | Sell |
291,467
-4,859
| -2% | -$1.09M | 0.43% | 60 |
|
|
2018
Q3 | $69.6M | Sell |
296,326
-1,163
| -0.4% | -$262K | 0.43% | 58 |
|
|
2018
Q2 | $62.2M | Sell |
297,489
-13,879
| -4% | -$2.74M | 0.42% | 57 |
|
|
2018
Q1 | $58.7M | Buy |
311,368
+8,020
| +3% | +$1.51M | 0.41% | 60 |
|
|
2017
Q4 | $56.5M | Sell |
303,348
-62,959
| -17% | -$10.9M | 0.38% | 64 |
|
|
2017
Q3 | $60.2M | Sell |
366,307
-210,138
| -36% | -$33M | 0.45% | 59 |
|
|
2017
Q2 | $92.2M | Sell |
576,445
-36,667
| -6% | -$6.32M | 0.69% | 32 |
|
|
2017
Q1 | $104M | Buy |
613,112
+26,929
| +5% | +$4.51M | 0.84% | 21 |
|
|
2016
Q4 | $93.9M | Buy |
586,183
+21,215
| +4% | +$3.24M | 0.84% | 23 |
|
|
2016
Q3 | $86.2M | Buy |
564,968
+118,820
| +27% | +$19.2M | 0.76% | 26 |
|
|
2016
Q2 | $70.1M | Buy |
446,148
+54,274
| +14% | +$8.22M | 0.65% | 39 |
|
|
2016
Q1 | $61.8M | Buy |
391,874
+18,968
| +5% | +$2.88M | 0.58% | 48 |
|
|
2015
Q4 | $60.2M | Sell |
372,906
-92,262
| -20% | -$14.6M | 0.57% | 46 |
|
|
2015
Q3 | $67.2M | Sell |
465,168
-603,699
| -56% | -$86.1M | 0.58% | 37 |
|
|
2015
Q2 | $144M | Sell |
1,068,867
-115,226
| -10% | -$16.6M | 0.22% | 142 |
|
|
2015
Q1 | $179M | Buy |
1,184,093
+40,449
| +4% | +$5.93M | 0.28% | 99 |
|
|
2014
Q4 | $162M | Sell |
1,143,644
-43,006
| -4% | -$5.85M | 0.26% | 118 |
|
|
2014
Q3 | $149M | Sell |
1,186,650
-22,072
| -2% | -$2.67M | 0.25% | 111 |
|
|
2014
Q2 | $139M | Sell |
1,208,722
-274,015
| -18% | -$31.4M | 0.23% | 137 |
|
|
2014
Q1 | $166M | Sell |
1,482,737
-178,338
| -11% | -$20.4M | 0.27% | 101 |
|
|
2013
Q4 | $198M | Sell |
1,661,075
-115,737
| -7% | -$13.8M | 0.33% | 69 |
|
|
2013
Q3 | $205M | Buy |
1,776,812
+67,604
| +4% | +$7.8M | 0.36% | 58 |
|
|
2013
Q2 | $189M | Buy |
+1,709,208
| New | +$187M | 0.37% | 60 |
|
Other funds holding COST
VCM
VPM
DAM
William Blair & Company's COST Position: Q1 2026 in Review
William Blair & Company increased its Costco (COST) stake by 0.02% in Q1 2026, buying an estimated $92.6K and bringing the position to 521,277 shares worth $519M. The position accounts for 1.49% of the portfolio, ranked #12.
William Blair & Company first reported a position in COST in Q2 2013 and has held it in 52 quarters since. The position peaked at $546M in Q2 2025. 4,238 funds tracked by Wall St. Rank hold COST as of Q1 2026.
- William Blair & Company held 521,277 shares of Costco worth $519M as of Q1 2026.
- William Blair & Company bought 95 Costco shares in Q1 2026, an estimated $92.6K.
- Costco made up 1.49% of William Blair & Company's portfolio in Q1 2026, its #12 holding.
- William Blair & Company first reported a position in Costco in Q2 2013 and has held it in 52 quarters since.
- William Blair & Company's Costco position peaked at $546M in Q2 2025.
- 4,238 funds tracked by Wall St. Rank held Costco as of Q1 2026.
Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.