William Blair & Company’s CoStar Group CSGP Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q1 | $36.3M | Sell |
900,313
-1,123,210
| -56% | -$58.5M | 0.1% | 172 |
|
|
2025
Q4 | $136M | Sell |
2,023,523
-1,104,950
| -35% | -$78.3M | 0.37% | 63 |
|
|
2025
Q3 | $264M | Buy |
3,128,473
+257,311
| +9% | +$22.7M | 0.7% | 30 |
|
|
2025
Q2 | $231M | Sell |
2,871,162
-32,356
| -1% | -$2.52M | 0.64% | 40 |
|
|
2025
Q1 | $230M | Sell |
2,903,518
-490,433
| -14% | -$37.3M | 0.69% | 35 |
|
|
2024
Q4 | $243M | Sell |
3,393,951
-456,885
| -12% | -$34.5M | 0.71% | 30 |
|
|
2024
Q3 | $291M | Sell |
3,850,836
-546,902
| -12% | -$41.5M | 0.85% | 24 |
|
|
2024
Q2 | $326M | Sell |
4,397,738
-22,040
| -0.5% | -$1.87M | 1.01% | 18 |
|
|
2024
Q1 | $427M | Buy |
4,419,778
+26,800
| +0.6% | +$2.31M | 1.34% | 11 |
|
|
2023
Q4 | $384M | Buy |
4,392,978
+201,969
| +5% | +$16.3M | 1.31% | 13 |
|
|
2023
Q3 | $322M | Buy |
4,191,009
+251,182
| +6% | +$20.8M | 1.24% | 14 |
|
|
2023
Q2 | $351M | Buy |
3,939,827
+184,794
| +5% | +$14.3M | 1.28% | 12 |
|
|
2023
Q1 | $259M | Buy |
3,755,033
+44,732
| +1% | +$3.3M | 1.03% | 16 |
|
|
2022
Q4 | $287M | Buy |
3,710,301
+256,608
| +7% | +$20.1M | 1.25% | 11 |
|
|
2022
Q3 | $241M | Buy |
3,453,693
+244,909
| +8% | +$17M | 1.1% | 14 |
|
|
2022
Q2 | $194M | Buy |
3,208,784
+453,649
| +16% | +$27.5M | 0.86% | 20 |
|
|
2022
Q1 | $184M | Sell |
2,755,135
-40,211
| -1% | -$2.67M | 0.64% | 36 |
|
|
2021
Q4 | $221M | Buy |
2,795,346
+71,440
| +3% | +$5.99M | 0.69% | 33 |
|
|
2021
Q3 | $234M | Buy |
2,723,906
+48,540
| +2% | +$4.2M | 0.8% | 23 |
|
|
2021
Q2 | $222M | Buy |
2,675,366
+48,906
| +2% | +$4.23M | 0.77% | 23 |
|
|
2021
Q1 | $216M | Buy |
2,626,460
+40,540
| +2% | +$3.5M | 0.81% | 23 |
|
|
2020
Q4 | $239M | Buy |
2,585,920
+12,240
| +0.5% | +$1.07M | 0.88% | 21 |
|
|
2020
Q3 | $218M | Buy |
2,573,680
+18,390
| +0.7% | +$1.47M | 0.93% | 21 |
|
|
2020
Q2 | $182M | Buy |
2,555,290
+45,720
| +2% | +$2.96M | 0.87% | 21 |
|
|
2020
Q1 | $147M | Sell |
2,509,570
-48,720
| -2% | -$3.18M | 0.92% | 19 |
|
|
2019
Q4 | $153M | Buy |
2,558,290
+37,590
| +1% | +$2.19M | 0.79% | 25 |
|
|
2019
Q3 | $150M | Sell |
2,520,700
-50,510
| -2% | -$3.02M | 0.86% | 21 |
|
|
2019
Q2 | $142M | Sell |
2,571,210
-19,320
| -0.7% | -$987K | 0.81% | 24 |
|
|
2019
Q1 | $121M | Buy |
2,590,530
+99,710
| +4% | +$4.12M | 0.74% | 26 |
|
|
2018
Q4 | $84M | Sell |
2,490,820
-42,150
| -2% | -$1.54M | 0.61% | 36 |
|
|
2018
Q3 | $107M | Sell |
2,532,970
-29,310
| -1% | -$1.25M | 0.65% | 35 |
|
|
2018
Q2 | $106M | Sell |
2,562,280
-162,780
| -6% | -$6.26M | 0.72% | 30 |
|
|
2018
Q1 | $98.8M | Sell |
2,725,060
-702,700
| -21% | -$24.2M | 0.7% | 33 |
|
|
2017
Q4 | $102M | Sell |
3,427,760
-83,480
| -2% | -$2.45M | 0.69% | 32 |
|
|
2017
Q3 | $94.2M | Sell |
3,511,240
-44,500
| -1% | -$1.24M | 0.71% | 30 |
|
|
2017
Q2 | $93.7M | Sell |
3,555,740
-107,570
| -3% | -$2.62M | 0.7% | 29 |
|
|
2017
Q1 | $75.2M | Buy |
3,663,310
+144,920
| +4% | +$2.94M | 0.61% | 39 |
|
|
2016
Q4 | $66.3M | Sell |
3,518,390
-3,210
| -0.1% | -$63K | 0.59% | 42 |
|
|
2016
Q3 | $76.3M | Buy |
3,521,600
+230,630
| +7% | +$4.91M | 0.67% | 32 |
|
|
2016
Q2 | $72M | Sell |
3,290,970
-102,800
| -3% | -$2.03M | 0.67% | 37 |
|
|
2016
Q1 | $63.9M | Buy |
3,393,770
+83,650
| +3% | +$1.48M | 0.6% | 45 |
|
|
2015
Q4 | $68.4M | Sell |
3,310,120
-521,660
| -14% | -$10.4M | 0.64% | 37 |
|
|
2015
Q3 | $66.3M | Sell |
3,831,780
-10,257,770
| -73% | -$196M | 0.57% | 38 |
|
|
2015
Q2 | $284M | Buy |
14,089,550
+62,970
| +0.4% | +$1.28M | 0.42% | 36 |
|
|
2015
Q1 | $277M | Sell |
14,026,580
-556,580
| -4% | -$10.5M | 0.43% | 37 |
|
|
2014
Q4 | $268M | Buy |
14,583,160
+1,880,460
| +15% | +$30.4M | 0.43% | 33 |
|
|
2014
Q3 | $198M | Sell |
12,702,700
-102,040
| -0.8% | -$1.52M | 0.34% | 68 |
|
|
2014
Q2 | $203M | Buy |
12,804,740
+3,198,720
| +33% | +$51.8M | 0.33% | 68 |
|
|
2014
Q1 | $179M | Buy |
9,606,020
+79,450
| +0.8% | +$1.5M | 0.3% | 89 |
|
|
2013
Q4 | $176M | Sell |
9,526,570
-1,097,660
| -10% | -$19.4M | 0.29% | 90 |
|
|
2013
Q3 | $178M | Sell |
10,624,230
-60,340
| -0.6% | -$926K | 0.32% | 71 |
|
|
2013
Q2 | $138M | Buy |
+10,684,570
| New | +$121M | 0.27% | 91 |
|
Other funds holding CSGP
VPM
VCM
William Blair & Company's CSGP Position: Q1 2026 in Review
William Blair & Company reduced its CoStar Group (CSGP) stake by 56% in Q1 2026, selling an estimated $58.5M and leaving 900,313 shares worth $36.3M. The position accounts for 0.1% of the portfolio, ranked #172.
William Blair & Company first reported a position in CSGP in Q2 2013 and has held it in 52 quarters since. The position peaked at $427M in Q1 2024. 793 funds tracked by Wall St. Rank hold CSGP as of Q1 2026.
- William Blair & Company held 900,313 shares of CoStar Group worth $36.3M as of Q1 2026.
- William Blair & Company sold 1,123,210 CoStar Group shares in Q1 2026, an estimated $58.5M.
- CoStar Group made up 0.1% of William Blair & Company's portfolio in Q1 2026, its #172 holding.
- William Blair & Company first reported a position in CoStar Group in Q2 2013 and has held it in 52 quarters since.
- William Blair & Company's CoStar Group position peaked at $427M in Q1 2024.
- 793 funds tracked by Wall St. Rank held CoStar Group as of Q1 2026.
Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.