CoStar Group, Inc.
MX ˙ BMV ˙ US22160N1090
DIESES SYMBOL IST NICHT MEHR AKTIV
SecurityMX:CSGP / CoStar Group, Inc.
InstitutionRhumbline Advisers
Latest Disclosed Ownership792,763 shares
Latest Disclosed Value $ 31,979,932
Rhumbline Advisers reports 3.11% increase in ownership of CSGP / CoStar Group, Inc.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 792,763 shares of CoStar Group, Inc. (MX:CSGP) valued at $31,979,932 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 768,835 shares of CoStar Group, Inc.. This represents a change in shares of 3.11% 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)
2026-05-12 2026-03-31 13F COSTAR GROUP INC COM COM 22160N109 792,763 23,928 3.11 31,980 -38.14 0.0274
2026-02-13 2025-12-31 13F COSTAR GROUP INC COM COM 22160N109 768,835 -21,028 -2.66 51,696 -22.42 0.0418
2025-11-06 2025-09-30 13F COSTAR GROUP INC COM COM 22160N109 789,863 7,695 0.98 66,641 5.97 0.0535
2025-08-12 2025-06-30 13F COSTAR GROUP INC COM COM 22160N109 782,168 13,802 1.80 62,886 3.30 0.0539
2025-05-29 2025-03-31 13F/A-1 COSTAR GROUP INC COM COM 22160N109 768,366 54,747 7.67 60,878 19.16 0.0569
2025-04-08 2025-03-31 13F COSTAR GROUP INC COM COM 22160N109 768,366 54,747 60,878 0.0569
2025-05-29 2024-12-31 13F/A-1 COSTAR GROUP INC COM COM 22160N109 713,619 -7,532 -1.04 51,088 -6.10 0.0457
2025-01-30 2024-12-31 13F COSTAR GROUP INC COM COM 22160N109 713,619 -7,532 51,088 0.0457
2024-11-12 2024-09-30 13F COSTAR GROUP INC COM COM 22160N109 721,151 -20,411 -2.75 54,404 -1.05 0.0491
2024-08-01 2024-06-30 13F COSTAR GROUP INC COM COM 22160N109 741,562 -43,377 -5.53 54,979 -27.49 0.0517
2024-05-09 2024-03-31 13F COSTAR GROUP INC COM COM 22160N109 784,939 11,566 1.50 75,825 12.19 0.0728
2024-02-08 2023-12-31 13F COSTAR GROUP INC COM COM 22160N109 773,373 -9,256 -1.18 67,585 12.31 0.0708
2023-11-09 2023-09-30 13F COSTAR GROUP INC COM COM 22160N109 782,629 -3,626 -0.46 60,176 -14.00 0.0699
2023-08-08 2023-06-30 13F COSTAR GROUP INC COM COM 22160N109 786,255 39,125 5.24 69,977 137,107.84 0.0784
2023-05-11 2023-03-31 13F COSTAR GROUP INC COM COM 22160N109 747,130 14,164 1.93 51 -99.91 0.0635
2023-02-14 2022-12-31 13F COSTAR GROUP INC COM COM 22160N109 732,966 57,442 8.50 56,644 20.39 0.0761
2022-11-10 2022-09-30 13F COSTAR GROUP INC COM COM 22160N109 675,524 287,319 74.01 47,050 100.63 0.0701
2022-08-11 2022-06-30 13F COSTAR GROUP INC COM COM 22160N109 388,205 33,459 9.43 23,451 -0.76 0.0342
2022-05-12 2022-03-31 13F COSTAR GROUP INC COM COM 22160N109 354,746 -12,404 -3.38 23,630 -18.56 0.0304
2022-02-10 2021-12-31 13F COSTAR GROUP INC COM COM 22160N109 367,150 9,241 2.58 29,016 -5.80 0.0356
2021-11-12 2021-09-30 13F COSTAR GROUP INC COM COM 22160N109 357,909 -8,531 -2.33 30,802 1.49 0.0417
2021-08-05 2021-06-30 13F COSTAR GROUP INC COM COM 22160N109 366,440 326,366 814.41 30,349 -7.85 0.0398
2021-05-06 2021-03-31 13F COSTAR GROUP INC COM COM 22160N109 40,074 -3,706 -8.47 32,936 -18.61 0.0447
2021-02-10 2020-12-31 13F COSTAR GROUP INC COM COM 22160N109 43,780 -1,898 -4.16 40,465 4.40 0.0558
2020-11-12 2020-09-30 13F COSTAR GROUP INC COM COM 22160N109 45,678 -1,747 -3.68 38,758 15.00 0.0607
2020-08-13 2020-06-30 13F COSTAR GROUP INC COM COM 22160N109 47,425 5,254 12.46 33,704 36.11 0.0563
2020-05-06 2020-03-31 13F COSTAR GROUP INC COM COM 22160N109 42,171 -2,831 -6.29 24,763 -8.03 0.0519
2020-02-05 2019-12-31 13F COSTAR GROUP INC COM COM 22160N109 45,002 1,249 2.85 26,925 3.74 0.0450
2019-10-23 2019-09-30 13F COSTAR GROUP INC COM COM 22160N109 43,753 -394 -0.89 25,954 6.11 0.0474
2019-08-14 2019-06-30 13F COSTAR GROUP INC COM COM 22160N109 44,147 6,021 15.79 24,460 37.55 0.0459
2019-05-01 2019-03-31 13F COSTAR GROUP INC COM COM 22160N109 38,126 -155 -0.40 17,783 37.70 0.0344
2019-01-31 2018-12-31 13F COSTAR GROUP INC COM COM 22160N109 38,281 -931 -2.37 12,914 -21.74 0.0281
2018-11-07 2018-09-30 13F COSTAR GROUP INC COM COM 22160N109 39,212 -1,037 -2.58 16,502 -0.64 0.0319
2018-08-06 2018-06-30 13F COSTAR GROUP INC COM COM 22160N109 40,249 3,679 10.06 16,608 25.22 0.0335
2018-05-02 2018-03-31 13F COSTAR GROUP INC COM COM 22160N109 36,570 -597 -1.61 13,263 20.17 0.0277
2018-02-09 2017-12-31 13F COSTAR GROUP INC COM COM 22160N109 37,167 2,121 6.05 11,037 17.40 0.0224
2017-11-06 2017-09-30 13F COSTAR GROUP INC COM COM 22160N109 35,046 -1,490 -4.08 9,401 -2.39 0.0204
2017-08-02 2017-06-30 13F COSTAR GROUP INC COM COM 22160N109 36,536 -916 -2.45 9,631 24.09 0.0220
2017-05-02 2017-03-31 13F COSTAR GROUP INC COM COM 22160N109 37,452 1,589 4.43 7,761 14.81 0.0181
2017-01-27 2016-12-31 13F COSTAR GROUP INC COM COM 22160N109 35,863 2,398 7.17 6,760 -6.71 0.0171
2016-11-08 2016-09-30 13F COSTAR GROUP INC COM COM 22160N109 33,465 1,253 3.89 7,246 2.88 0.0200
2016-08-11 2016-06-30 13F COSTAR GROUP INC COM COM 22160N109 32,212 2,359 7.90 7,043 25.39 0.0209
2016-05-02 2016-03-31 13F COSTAR GROUP INC COM 22160N109 29,853 -242 -0.80 5,617 -9.69 0.0174
2016-02-03 2015-12-31 13F COSTAR GROUP INC COM 22160N109 30,095 875 2.99 6,220 23.00 0.0200
2015-11-04 2015-09-30 13F COSTAR GROUP INC COM 22160N109 29,220 1,178 4.20 5,057 -10.40 0.0172
2015-08-04 2015-06-30 13F COSTAR GROUP INC COM 22160N109 28,042 3,028 12.11 5,644 14.04 0.0180
2015-05-12 2015-03-31 13F COSTAR GROUP INC COM 22160N109 25,014 597 2.45 4,949 10.37 0.0143
2015-02-06 2014-12-31 13F COSTAR GROUP INC COM 22160N109 24,417 231 0.96 4,484 19.19 0.0130
2014-11-12 2014-09-30 13F COSTAR GROUP INC COM 22160N109 24,186 1,761 7.85 3,762 6.06 0.0113
2014-08-06 2014-06-30 13F COSTAR GROUP INC COM 22160N109 22,425 -9,400 -29.54 3,547 -40.32 0.0104
2014-05-06 2014-03-31 13F COSTAR GROUP INC COM 22160N109 31,825 -1,602 -4.79 5,943 -3.68 0.0176
2014-02-03 2013-12-31 13F COSTAR GROUP INC COM 22160N109 33,427 143 0.43 6,170 10.42 0.0182
2013-11-05 2013-09-30 13F COSTAR GROUP INC COM 22160N109 33,284 -141 -0.42 5,588 29.53 0.0173
2013-08-07 2013-06-30 13F COSTAR GROUP INC COM 22160N109 33,425 33,425 4,314 0.0139
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.