CoStar Group, Inc.
MX ˙ BMV ˙ US22160N1090
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT
SecurityMX:CSGP / CoStar Group, Inc.
InstitutionRussell Investments Group, Ltd.
Latest Disclosed Ownership349,783 shares
Latest Disclosed Value $ 14,128,571
Russell Investments Group, Ltd. reports 36.12% decrease in ownership of CSGP / CoStar Group, Inc.

On May 8, 2026 - Russell Investments Group, Ltd. filed a 13F-HR form disclosing ownership of 349,783 shares of CoStar Group, Inc. (MX:CSGP) valued at $14,128,571 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 547,600 shares of CoStar Group, Inc.. This represents a change in shares of -36.12% during the quarter.

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)
2026-05-08 2026-03-31 13F COSTAR GROUP Common Stock 22160N109 349,783 -197,817 -36.12 14,129 -61.65 0.0152
2026-02-17 2025-12-31 13F COSTAR GROUP Common Stock 22160N109 547,600 72,177 15.18 36,840 -8.15 0.0401
2025-11-13 2025-09-30 13F COSTAR GROUP Common Stock 22160N109 475,423 28,432 6.36 40,108 11.57 0.0455
2025-08-13 2025-06-30 13F COSTAR GROUP Common Stock 22160N109 446,991 22,195 5.22 35,949 6.80 0.0458
2025-05-13 2025-03-31 13F COSTAR GROUP Common Stock 22160N109 424,796 112,665 36.10 33,659 50.59 0.0463
2025-02-13 2024-12-31 13F COSTAR GROUP Common Stock 22160N109 312,131 26,623 9.32 22,353 3.85 0.0309
2024-11-13 2024-09-30 13F COSTAR GROUP Common Stock 22160N109 285,508 -2,534 -0.88 21,525 0.77 0.0312
2024-08-08 2024-06-30 13F COSTAR GROUP Common Stock 22160N109 288,042 -113,272 -28.23 21,361 -44.88 0.0344
2024-05-08 2024-03-31 13F COSTAR GROUP Common Stock 22160N109 401,314 55,763 16.14 38,750 28.23 0.0611
2024-02-05 2023-12-31 13F COSTAR GROUP Common Stock 22160N109 345,551 -83,262 -19.42 30,221 -8.34 0.0538
2023-11-13 2023-09-30 13F COSTAR GROUP Common Stock 22160N109 428,813 -132,774 -23.64 32,969 -34.08 0.0653
2023-08-10 2023-06-30 13F COSTAR GROUP Common Stock 22160N109 561,587 -40,668 -6.75 50,016 20.69 0.0965
2023-05-09 2023-03-31 13F COSTAR GROUP Common Stock 22160N109 602,255 -153,574 -20.32 41,442 -29.07 0.0813
2023-02-08 2022-12-31 13F COSTAR GROUP Common Stock 22160N109 755,829 89,261 13.39 58,424 25.74 0.1203
2022-11-04 2022-09-30 13F COSTAR GROUP Common Stock 22160N109 666,568 526,389 375.51 46,463 449.40 0.1021
2022-07-29 2022-06-30 13F COSTAR GROUP Common Stock 22160N109 140,179 -25,841 -15.56 8,457 -23.88 0.0173
2022-05-05 2022-03-31 13F COSTAR GROUP Common Stock 22160N109 166,020 -39,819 -19.34 11,110 -31.89 0.0193
2022-01-21 2021-12-31 13F COSTAR GROUP Common Stock 22160N109 205,839 -88,986 -30.18 16,311 -35.65 0.0261
2021-11-08 2021-09-30 13F COSTAR GROUP Common Stock 22160N109 294,825 -6,873 -2.28 25,349 1.42 0.0428
2021-08-04 2021-06-30 13F COSTAR GROUP Common Stock 22160N109 301,698 273,549 971.79 24,994 8.34 0.0418
2021-05-10 2021-03-31 13F CoStar Group Common Stock 22160N109 28,149 4,748 20.29 23,071 6.67 0.0408
2021-02-08 2020-12-31 13F CoStar Group Common Stock 22160N109 23,401 -4,845 -17.15 21,629 -9.94 0.0428
2020-11-09 2020-09-30 13F CoStar Group Common Stock 22160N109 28,246 1,636 6.15 24,017 27.35 0.0517
2020-08-05 2020-06-30 13F COSTAR GROUP Common Stock 22160N109 26,610 -8,590 -24.40 18,859 -8.85 0.0420
2020-05-06 2020-03-31 13F/A-1 CoStar Group Common Stock 22160N109 35,200 -5,988 -14.54 20,691 -16.01 0.0536
2020-05-06 2020-03-31 13F CoStar Group Common Stock 22160N109 35,200 -5,988 20,691 11,300.6008
2020-01-29 2019-12-31 13F CoStar Group Common Stock 22160N109 41,188 -40,788 -49.76 24,634 -48.95 0.0459
2019-11-01 2019-09-30 13F CoStar Group Common Stock 22160N109 81,976 -13,644 -14.27 48,254 -8.38 0.0936
2019-08-09 2019-06-30 13F CoStar Group Common Stock 22160N109 95,620 -16,939 -15.05 52,665 0.64 0.0983
2019-05-13 2019-03-31 13F CoStar Group Common Stock 22160N109 112,559 25,011 28.57 52,330 77.22 0.0967
2019-02-11 2018-12-31 13F CoStar Group Common Stock 22160N109 87,548 -16,410 -15.79 29,528 -32.36 0.0661
2018-10-26 2018-09-30 13F CoStar Group Common Stock 22160N109 103,958 2,479 2.44 43,653 4.05 0.0827
2018-08-08 2018-06-30 13F CoStar Group Common Stock 22160N109 101,479 -62,243 -38.02 41,955 -29.16 0.0875
2018-05-11 2018-03-31 13F COSTAR GROUP INC COM Common Stocks 22160N109 163,722 -28,817 -14.97 59,225 4.10 0.1002
2018-02-06 2017-12-31 13F COSTAR GROUP INC COM Common Stocks 22160N109 192,539 -28,309 -12.82 56,890 -3.96 0.0954
2017-11-07 2017-09-30 13F COSTAR GROUP INC COM Common Stocks 22160N109 220,848 22,629 11.42 59,236 13.35 0.1012
2017-07-25 2017-06-30 13F COSTAR GROUP INC COM Common Stocks 22160N109 198,219 -23,567 -10.63 52,260 13.70 0.0928
2017-04-26 2017-03-31 13F COSTAR GROUP INC COM Common Stocks 22160N109 221,786 62,457 39.20 45,962 53.54 0.0843
2017-01-23 2016-12-31 13F COSTAR GROUP INC COM Common Stocks 22160N109 159,329 159,329 29,934 0.0584
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.