CoStar Group, Inc.
US ˙ NasdaqGS ˙ US22160N1090

SecurityCSGP / CoStar Group, Inc.
InstitutionOppenheimer Asset Management Inc.
Latest Disclosed Ownership342,673 shares
Latest Disclosed Value $ 13,823,428
Oppenheimer Asset Management Inc. reports 42.78% increase in ownership of CSGP / CoStar Group, Inc.

On April 23, 2026 - Oppenheimer Asset Management Inc. filed a 13F-HR form disclosing ownership of 342,673 shares of CoStar Group, Inc. (US:CSGP) valued at $13,823,429 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 239,995 shares of CoStar Group, Inc.. This represents a change in shares of 42.78% during the quarter. The current value of the position is $11,613,188 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-04-23 2026-03-31 13F COSTAR GROUP COM 22160N109 342,673 102,678 42.78 13,823 -14.34 0.0395
2026-02-02 2025-12-31 13F COSTAR GROUP COM 22160N109 239,995 -34,750 -12.65 16,137 -30.38 0.0488
2025-11-06 2025-09-30 13F COSTAR GROUP COM 22160N109 274,745 -11,765 -4.11 23,180 0.63 0.2550
2025-07-31 2025-06-30 13F COSTAR GROUP COM 22160N109 286,510 5,758 2.05 23,035 3.56 0.2642
2025-04-23 2025-03-31 13F COSTAR GROUP COM 22160N109 280,752 8,619 3.17 22,244 14.17 0.2760
2025-02-05 2024-12-31 13F COSTAR GROUP COM 22160N109 272,133 114,003 72.09 19,482 63.32 0.2368
2024-11-05 2024-09-30 13F COSTAR GROUP COM 22160N109 158,130 -2,205 -1.38 11,929 0.35 0.1436
2024-08-08 2024-06-30 13F COSTAR GROUP COM 22160N109 160,335 9,829 6.53 11,887 -18.23 0.1519
2024-05-07 2024-03-31 13F COSTAR GROUP COM 22160N109 150,506 -30,964 -17.06 14,539 -8.32 0.2130
2024-02-13 2023-12-31 13F COSTAR GROUP COM 22160N109 181,470 2,586 1.45 15,859 15.30 0.2206
2023-11-08 2023-09-30 13F COSTAR GROUP COM 22160N109 178,884 -10,268 -5.43 13,754 -18.30 0.2111
2023-08-03 2023-06-30 13F COSTAR GROUP COM 22160N109 189,152 -6,076 -3.11 16,835 25.24 0.2476
2023-05-10 2023-03-31 13F COSTAR GROUP COM 22160N109 195,228 -2,841 -1.43 13,441 -12.18 0.2070
2023-02-07 2022-12-31 13F COSTAR GROUP COM 22160N109 198,069 -5,265 -2.59 15,307 8.08 0.2464
2022-11-14 2022-09-30 13F COSTAR GROUP COM 22160N109 203,334 -2,242 -1.09 14,162 14.03 0.2498
2022-08-08 2022-06-30 13F COSTAR GROUP COM 22160N109 205,576 -6,698 -3.16 12,419 -12.16 0.2081
2022-05-12 2022-03-31 13F COSTAR GROUP COM 22160N109 212,274 16,706 8.54 14,139 -8.52 0.2007
2022-02-02 2021-12-31 13F COSTAR GROUP COM 22160N109 195,568 -1,351 -0.69 15,456 -8.79 0.2049
2021-11-12 2021-09-30 13F COSTAR GROUP COM 22160N109 196,919 1,482 0.76 16,946 4.70 0.2410
2021-08-03 2021-06-30 13F COSTAR GROUP COM 22160N109 195,437 176,305 921.52 16,186 2.94 0.2305
2021-05-17 2021-03-31 13F COSTAR GROUP COM 22160N109 19,132 693 3.76 15,724 -7.74 0.2437
2021-02-11 2020-12-31 13F COSTAR GROUP COM 22160N109 18,439 331 1.83 17,043 10.92 0.2846
2020-11-13 2020-09-30 13F COSTAR GROUP COM 22160N109 18,108 -1,145 -5.95 15,365 12.30 0.2983
2020-08-11 2020-06-30 13F COSTAR GROUP COM 22160N109 19,253 707 3.81 13,682 25.64 0.2823
2020-05-08 2020-03-31 13F COSTAR GROUP COM 22160N109 18,546 194 1.06 10,890 -0.82 0.2675
2020-02-07 2019-12-31 13F COSTAR GROUP COM 22160N109 18,352 67 0.37 10,980 1.24 0.2320
2019-10-31 2019-09-30 13F COSTAR GROUP COM 22160N109 18,285 -1,763 -8.79 10,846 -2.36 0.2409
2019-08-09 2019-06-30 13F COSTAR GROUP COM 22160N109 20,048 -52 -0.26 11,108 18.47 0.2454
2019-04-24 2019-03-31 13F COSTAR GROUP COM 22160N109 20,100 928 4.84 9,376 44.98 0.2106
2019-01-30 2018-12-31 13F COSTAR GROUP COM 22160N109 19,172 448 2.39 6,467 -17.93 0.1602
2018-10-26 2018-09-30 13F COSTAR GROUP COM 22160N109 18,724 -1,521 -7.51 7,880 -5.67 0.1746
2018-08-10 2018-06-30 13F COSTAR GROUP COM 22160N109 20,245 1,121 5.86 8,354 20.46 0.2043
2018-05-09 2018-03-31 13F COSTAR GROUP COM 22160N109 19,124 -3,723 -16.30 6,935 13.15 0.1740
2018-02-07 2017-12-31 13F COSTAR GROUP COM 22160N109 22,847 0 0.00 6,129 0.00 0.1626
2017-11-14 2017-09-30 13F COSTAR GROUP COM 22160N109 22,847 476 2.13 6,129 3.93 0.1592
2017-08-09 2017-06-30 13F COSTAR GROUP COM 22160N109 22,371 -841 -3.62 5,897 22.62 0.1629
2017-05-15 2017-03-31 13F COSTAR GROUP COM 22160N109 23,212 23,212 4,809 0.1370
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.