CoStar Group, Inc.
US ˙ NasdaqGS ˙ US22160N1090

SecurityCSGP / CoStar Group, Inc.
InstitutionAdvisor Group Holdings, Inc.
Latest Disclosed Ownership30,503 shares
Latest Disclosed Value $ 1,230,459
Advisor Group Holdings, Inc. reports 132.69% increase in ownership of CSGP / CoStar Group, Inc.

On May 15, 2026 - Advisor Group Holdings, Inc. filed a 13F-HR form disclosing ownership of 30,503 shares of CoStar Group, Inc. (US:CSGP) valued at $1,230,491 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 13,109 shares of CoStar Group, Inc.. This represents a change in shares of 132.69% during the quarter. The current value of the position is $1,018,800 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 30,503 17,394 132.69 1,230 39.61 0.0010
2026-02-17 2025-12-31 13F COSTAR GROUP COM 22160N109 13,109 -29,984 -69.58 881 -75.94 0.0013
2025-11-14 2025-09-30 13F COSTAR GROUP COM 22160N109 43,093 -409 -0.94 3,662 5.60 0.0051
2025-09-04 2025-06-30 13F/A-1 OSTAR GROUP COM 22160N109 43,502 29,477 210.17 3,467 212.06 0.0062
2025-08-13 2025-06-30 13F OSTAR GROUP COM 22160N109 41,276 27,251 3,239 0.0037
2025-05-12 2025-03-31 13F COSTAR GROUP COM 22160N109 14,025 -1,184 -7.78 1,111 2.11 0.0025
2025-06-06 2024-12-31 13F/A-1 COSTAR GROUP COM 22160N109 15,209 -10,015 -39.70 1,089 -42.80 0.0024
2025-02-07 2024-12-31 13F COSTAR GROUP COM 22160N109 14,475 -10,749 1,055 0.0027
2024-11-13 2024-09-30 13F COSTAR GROUP COM 22160N109 25,224 30 0.12 1,903 1.87 0.0043
2024-08-13 2024-06-30 13F COSTAR GROUP COM 22160N109 25,194 -2,953 -10.49 1,868 -31.34 0.0044
2024-05-10 2024-03-31 13F COSTAR GROUP COM 22160N109 28,147 -100,834 -78.18 2,719 -75.87 0.0061
2024-02-12 2023-12-31 13F COSTAR GROUP COM 22160N109 128,981 -19,628 -13.21 11,271 -1.36 0.0197
2023-11-13 2023-09-30 13F COSTAR GROUP COM 22160N109 148,609 37,294 33.50 11,426 15.33 0.0169
2023-08-21 2023-06-30 13F/A-1 COSTAR GROUP COM 22160N109 111,315 788 0.71 9,906 30.21 0.0178
2023-08-10 2023-06-30 13F COSTAR GROUP COM 22160N109 114,395 3,868 9,903 0.0027
2023-05-12 2023-03-31 13F COSTAR GROUP COM 22160N109 110,527 -2,408 -2.13 7,609 -12.82 0.0143
2023-02-10 2022-12-31 13F COSTAR GROUP COM 22160N109 112,935 -15,023 -11.74 8,727 -2.08 0.0177
2022-11-14 2022-09-30 13F COSTAR GROUP COM 22160N109 127,958 -23,581 -15.56 8,912 -2.66 0.0204
2022-08-10 2022-06-30 13F COSTAR GROUP COM 22160N109 151,539 5,664 3.88 9,156 -15.23 0.0202
2022-05-04 2022-03-31 13F COSTAR GROUP COM 22160N109 145,875 17,925 14.01 10,801 6.82 0.0210
2022-02-03 2021-12-31 13F COSTAR GROUP COM 22160N109 127,950 3,794 3.06 10,111 -5.36 0.0191
2021-11-05 2021-09-30 13F COSTAR GROUP COM 22160N109 124,156 6,866 5.85 10,684 9.97 0.0223
2021-08-02 2021-06-30 13F COSTAR GROUP COM 22160N109 117,290 105,869 926.97 9,715 3.46 0.0210
2021-05-13 2021-03-31 13F COSTAR GROUP COM 22160N109 11,421 874 8.29 9,390 -3.64 0.0226
2021-02-10 2020-12-31 13F COSTAR GROUP COM 22160N109 10,547 1,980 23.11 9,745 34.30 0.0260
2020-11-12 2020-09-30 13F COSTAR GROUP COM 22160N109 8,567 1,723 25.18 7,256 49.15 0.0217
2020-08-14 2020-06-30 13F COSTAR GROUP COM 22160N109 6,844 2,158 46.05 4,865 77.23 0.0163
2020-05-18 2020-03-31 13F COSTAR GROUP COM 22160N109 4,686 4,686 2,745 0.0112
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.