CoStar Group, Inc.
US ˙ NasdaqGS ˙ US22160N1090

SecurityCSGP / CoStar Group, Inc.
InstitutionFmr Llc
Latest Disclosed Ownership2,831,524 shares
Latest Disclosed Value $ 114,223,699
Fmr Llc reports 135.54% increase in ownership of CSGP / CoStar Group, Inc.

On May 15, 2026 - Fmr Llc filed a 13F-HR form disclosing ownership of 2,831,524 shares of CoStar Group, Inc. (US:CSGP) valued at $114,223,678 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 1,202,153 shares of CoStar Group, Inc.. This represents a change in shares of 135.54% during the quarter. The current value of the position is $94,572,902 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F COSTAR GROUP COM 22160N109 2,831,524 1,629,371 135.54 114,224 41.31 0.0012
2026-02-17 2025-12-31 13F COSTAR GROUP COM 22160N109 1,202,153 -378,001 -23.92 80,833 -39.37 0.0041
2025-11-13 2025-09-30 13F COSTAR GROUP COM 22160N109 1,580,154 284,277 21.94 133,318 27.96 0.0069
2025-08-14 2025-06-30 13F COSTAR GROUP COM 22160N109 1,295,877 -342,770 -20.92 104,189 -19.75 0.0059
2025-05-12 2025-03-31 13F COSTAR GROUP COM 22160N109 1,638,647 476,633 41.02 129,830 56.07 0.0083
2025-02-13 2024-12-31 13F COSTAR GROUP COM 22160N109 1,162,014 -435,414 -27.26 83,189 -30.97 0.0050
2024-11-13 2024-09-30 13F COSTAR GROUP COM 22160N109 1,597,428 -9,068 -0.56 120,510 1.18 0.0073
2024-08-13 2024-06-30 13F COSTAR GROUP COM 22160N109 1,606,496 509,125 46.39 119,106 12.36 0.0076
2024-05-13 2024-03-31 13F COSTAR GROUP COM 22160N109 1,097,371 -487,851 -30.77 106,006 -23.48 0.0071
2024-02-13 2023-12-31 13F COSTAR GROUP COM 22160N109 1,585,222 179,808 12.79 138,533 28.20 0.0106
2023-11-13 2023-09-30 13F COSTAR GROUP COM 22160N109 1,405,414 638,241 83.19 108,062 58.27 0.0093
2023-08-11 2023-06-30 13F COSTAR GROUP COM 22160N109 767,173 43,030 5.94 68,278 36.95 0.0057
2023-08-11 2023-03-31 13F/A-1 COSTAR GROUP COM 22160N109 724,143 -484,275 -40.08 49,857 -46.61 0.0046
2023-05-11 2023-03-31 13F COSTAR GROUP COM 22160N109 724,143 -484,275 49,857 0.0009
2023-02-13 2022-12-31 13F COSTAR GROUP COM 22160N109 1,208,418 -44,681 -3.57 93,387 7.00 0.0093
2022-11-10 2022-09-30 13F COSTAR GROUP COM 22160N109 1,253,099 -162,919 -11.51 87,279 2.03 0.0091
2022-08-12 2022-06-30 13F COSTAR GROUP COM 22160N109 1,416,018 382,001 36.94 85,542 24.20 0.0085
2022-05-13 2022-03-31 13F COSTAR GROUP COM 22160N109 1,034,017 -242,471 -19.00 68,875 -31.73 0.0055
2022-02-14 2021-12-31 13F COSTAR GROUP COM 22160N109 1,276,488 -1,703 -0.13 100,880 -8.29 0.0074
2022-02-14 2021-09-30 13F/A-1 COSTAR GROUP COM 22160N109 1,278,191 -454,251 -26.22 110,002 -23.33 0.0087
2021-11-15 2021-09-30 13F COSTAR GROUP COM 22160N109 1,278,191 -454,251 110,002 0.0087
2021-08-13 2021-06-30 13F COSTAR GROUP COM 22160N109 1,732,442 1,331,664 332.27 143,482 -56.44 0.0112
2021-05-14 2021-03-31 13F COSTAR GROUP COM 22160N109 400,778 -476,837 -54.33 329,397 -59.39 0.0281
2021-02-08 2020-12-31 13F COSTAR GROUP COM 22160N109 877,615 47,629 5.74 811,163 15.18 0.0722
2020-11-13 2020-09-30 13F COSTAR GROUP COM 22160N109 829,986 69,339 9.12 704,251 30.28 0.0712
2020-08-24 2020-06-30 13F/A-1 COSTAR GROUP COM 22160N109 760,647 -30,842 -3.90 540,568 16.31 0.0594
2020-08-13 2020-06-30 13F COSTAR GROUP COM 22160N109 760,647 -30,842 540,568 13,280.1739
2020-05-14 2020-03-31 13F COSTAR GROUP COM 22160N109 791,489 410,606 107.80 464,770 103.95 0.0644
2020-02-07 2019-12-31 13F COSTAR GROUP COM 22160N109 380,883 -299,545 -44.02 227,883 -43.54 0.0251
2019-11-13 2019-09-30 13F COSTAR GROUP COM 22160N109 680,428 187,934 38.16 403,631 47.92 0.0484
2019-08-13 2019-06-30 13F COSTAR GROUP COM 22160N109 492,494 180,634 57.92 272,871 87.59 0.0319
2019-05-13 2019-03-31 13F COSTAR GROUP COM 22160N109 311,860 68,023 27.90 145,458 76.84 0.0174
2019-02-13 2018-12-31 13F COSTAR GROUP COM 22160N109 243,837 103,268 73.46 82,256 39.05 0.0113
2018-11-09 2018-09-30 13F COSTAR GROUP COM 22160N109 140,569 -151,826 -51.92 59,157 -50.97 0.0067
2018-08-10 2018-06-30 13F COSTAR GROUP COM 22160N109 292,395 93,891 47.30 120,651 67.59 0.0142
2018-05-14 2018-03-31 13F COSTAR GROUP COM 22160N109 198,504 118,105 146.90 71,993 201.55 0.0085
2018-02-12 2017-12-31 13F COSTAR GROUP COM 22160N109 80,399 -12,001 -12.99 23,874 -3.68 0.0028
2017-11-13 2017-09-30 13F COSTAR GROUP COM 22160N109 92,400 -262,900 -73.99 24,786 -73.54 0.0030
2017-08-29 2017-06-30 13F/A-1 COSTAR GROUP COM 22160N109 355,300 -122,200 -25.59 93,657 -5.35 0.0116
2017-08-11 2017-06-30 13F COSTAR GROUP COM 22160N109 355,300 -122,200 93,657
2017-05-11 2017-03-31 13F COSTAR GROUP COM 22160N109 477,500 31,000 6.94 98,947 17.57 0.0126
2017-02-10 2016-12-31 13F COSTAR GROUP COM 22160N109 446,500 394,486 758.42 84,161 647.23 0.0112
2016-11-14 2016-09-30 13F COSTAR GROUP COM 22160N109 52,014 15,000 40.53 11,263 39.17 0.0015
2016-08-11 2016-06-30 13F COSTAR GROUP COM 22160N109 37,014 37,014 0.00 8,093 0.0011
2015-08-13 2015-06-30 13F COSTAR GROUP COM 22160N109 0 -146,089 -100.00 0 -100.00
2015-05-14 2015-03-31 13F COSTAR GROUP COM 22160N109 146,089 -132,780 -47.61 28,901 -43.56 0.0037
2015-02-17 2014-12-31 13F COSTAR GROUP COM 22160N109 278,869 -78,400 -21.94 51,208 -7.85 0.0067
2014-11-14 2014-09-30 13F COSTAR GROUP COM 22160N109 357,269 -75,018 -17.35 55,570 -18.73 0.0075
2014-08-14 2014-06-30 13F COSTAR GROUP COM 22160N109 432,287 67,157 18.39 68,375 0.28 0.0092
2014-05-15 2014-03-31 13F COSTAR GROUP COM 22160N109 365,130 -414,092 -53.14 68,184 -52.59 0.0095
2014-02-13 2013-12-31 13F COSTAR GROUP COM 22160N109 779,222 -125,970 -13.92 143,829 -5.36 0.0203
2013-11-14 2013-09-30 13F COSTAR GROUP COM 22160N109 905,192 181,126 25.02 151,982 62.63 0.0233
2013-09-24 2013-06-30 13F/A-1 COSTAR GROUP COM 22160N109 724,066 724,066 93,455 0.0153
2013-08-14 2013-06-30 13F COSTAR GROUP COM 22160N109 724,066 93,455 0.0153
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.