CoStar Group, Inc.
US ˙ NasdaqGS ˙ US22160N1090

SecurityCSGP / CoStar Group, Inc.
InstitutionWalleye Capital LLC
Latest Disclosed Ownership536,787 shares
Latest Disclosed Value $ 21,653,988
Walleye Capital LLC ownership in CSGP / CoStar Group, Inc.

On May 13, 2026 - Walleye Capital LLC filed a 13F-HR/A form disclosing ownership of 536,787 shares of CoStar Group, Inc. (US:CSGP) valued at $21,653,988 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 32,462 shares of CoStar Group, Inc.. This represents a change in shares of 1,553.59% during the quarter. The current value of the position is $17,928,686 USD.

Walleye Capital LLC has a history of taking positions in derivatives of the underlying security (CSGP) in the form of stock options. The firm currently holds call options representing 65,000 of underlying shares valued at $2,622,100 USD and put options representing 80,200 of underlying shares valued at $3,235,268 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

CSGP / CoStar Group, Inc. Historical Put/Call Ratio
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)
2026-05-13 2026-03-31 13F/A-1 COSTAR GROUP COM 22160N109 536,787 504,325 1,553.59 21,654 892.35 0.0901
2026-05-08 2026-03-31 13F COSTAR GROUP COM 22160N109 536,787 504,325 21,654 0.0900
2026-02-13 2025-12-31 13F COSTAR GROUP COM 22160N109 32,462 17,100 111.31 2,183 68.36 0.0067
2025-11-14 2025-09-30 13F COSTAR GROUP COM 22160N109 15,362 8,055 110.24 1,296 120.78 0.0049
2025-08-13 2025-06-30 13F COSTAR GROUP COM 22160N109 7,307 -10,219 -58.31 587 -57.71 0.0023
2025-05-14 2025-03-31 13F COSTAR GROUP COM 22160N109 17,526 17,526 1,389 0.0063
2025-02-13 2024-12-31 13F COSTAR GROUP COM 22160N109 0 -155,813 -100.00 0 -100.00
2024-11-14 2024-09-30 13F COSTAR GROUP COM 22160N109 155,813 31,492 25.33 11,755 27.53 0.0245
2024-08-14 2024-06-30 13F COSTAR GROUP COM 22160N109 124,321 -21,114 -14.52 9,217 -34.39 0.0164
2024-05-15 2024-03-31 13F COSTAR GROUP COM 22160N109 145,435 57,474 65.34 14,049 82.79 0.0250
2024-02-14 2023-12-31 13F COSTAR GROUP COM 22160N109 87,961 -56,070 -38.93 7,687 -30.59 0.0163
2023-11-21 2023-09-30 13F/A-1 COSTAR GROUP COM 22160N109 144,031 126,219 708.62 11,075 598.68 0.0283
2023-11-14 2023-09-30 13F COSTAR GROUP COM 22160N109 144,031 126,219 11,075 0.0285
2023-08-14 2023-06-30 13F COSTAR GROUP COM 22160N109 17,812 17,812 1,585 0.0057
2023-05-15 2023-03-31 13F COSTAR GROUP COM 22160N109 0 -61,563 -100.00 0 -100.00
2023-02-14 2022-12-31 13F COSTAR GROUP COM 22160N109 61,563 17,062 38.34 4,758 53.50 0.0868
2022-11-14 2022-09-30 13F COSTAR GROUP COM 22160N109 44,501 44,501 3,099 0.0591
2022-08-19 2022-06-30 13F/A-1 COSTAR GROUP COM 22160N109 0 -10,028 -100.00 0 -100.00
2022-08-08 2022-06-30 13F COSTAR GROUP COM 22160N109 0 -10,028 0
2022-05-27 2022-03-31 13F/A-01 COSTAR GROUP COM 22160N109 10,028 10,028 668 0.0179
2022-05-16 2022-03-31 13F COSTAR GROUP COM 22160N109 10,028 10,028 668 0.0136
2021-11-15 2021-09-30 13F COSTAR GROUP COM 22160N109 0 -10,035 -100.00 0 -100.00
2021-08-16 2021-06-30 13F COSTAR GROUP COM 22160N109 10,035 10,035 831 0.0283
2021-02-16 2020-12-31 13F COSTAR GROUP COM 22160N109 0 -253 -100.00 0 -100.00
2020-11-16 2020-09-30 13F COSTAR GROUP COM 22160N109 253 253 215 0.0240
2020-08-14 2020-06-30 13F COSTAR GROUP COM 22160N109 0 -389 -100.00 0 -100.00
2020-05-15 2020-03-31 13F COSTAR GROUP COM 22160N109 389 389 228 0.0502
2020-02-14 2019-12-31 13F COSTAR GROUP COM 22160N109 0 -42 -100.00 0 -100.00
2019-11-14 2019-09-30 13F COSTAR GROUP COM 22160N109 42 42 25 0.0015
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-13 2026-03-31 13F/A COSTAR GROUP COM Call 65,000 -2.26 2,622 -41.36 n/a n/a n/a
2026-05-08 2026-03-31 13F COSTAR GROUP COM Call 65,000 2,622 n/a n/a n/a
2026-02-13 2025-12-31 13F COSTAR GROUP COM Call 66,500 1,650.00 4,471 1,297.19 n/a n/a n/a
2025-11-14 2025-09-30 13F COSTAR GROUP COM Call 3,800 -35.59 321 -32.49 n/a n/a n/a
2025-08-13 2025-06-30 13F COSTAR GROUP COM Call 5,900 -84.43 474 -84.21 n/a n/a n/a
2025-05-14 2025-03-31 13F COSTAR GROUP COM Call 37,900 -32.20 3,003 -24.97 n/a n/a n/a
2025-02-13 2024-12-31 13F COSTAR GROUP COM Call 55,900 -32.16 4,002 -35.63 n/a n/a n/a
2024-11-14 2024-09-30 13F COSTAR GROUP COM Call 82,400 70.60 6,216 73.63 n/a n/a n/a
2024-08-14 2024-06-30 13F COSTAR GROUP COM Call 48,300 117.57 3,581 66.98 n/a n/a n/a
2024-05-15 2024-03-31 13F COSTAR GROUP COM Call 22,200 119.80 2,145 143.08 n/a n/a n/a
2024-02-14 2023-12-31 13F COSTAR GROUP COM Call 10,100 -80.58 883 -77.94 n/a n/a n/a
2023-11-21 2023-09-30 13F/A COSTAR GROUP COM Call 52,000 124.14 3,998 93.70 n/a n/a n/a
2023-11-14 2023-09-30 13F COSTAR GROUP COM Call 52,000 3,998 n/a n/a n/a
2023-08-14 2023-06-30 13F COSTAR GROUP COM Call 23,200 293.22 2,065 408.37 n/a n/a n/a
2023-05-15 2023-03-31 13F COSTAR GROUP COM Call 5,900 -50.00 406 -55.43 n/a n/a n/a
2023-02-14 2022-12-31 13F COSTAR GROUP COM Call 11,800 306.90 912 350.99 n/a n/a n/a
2022-11-14 2022-09-30 13F COSTAR GROUP COM Call 2,900 202 n/a n/a n/a
2020-02-14 2019-12-31 13F COSTAR GROUP COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F COSTAR GROUP COM Call 200 119 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-13 2026-03-31 13F/A COSTAR GROUP COM Put 80,200 -3.84 3,235 -42.30 n/a n/a n/a
2026-05-08 2026-03-31 13F COSTAR GROUP COM Put 80,200 3,235 n/a n/a n/a
2026-02-13 2025-12-31 13F COSTAR GROUP COM Put 83,400 172.55 5,608 117.24 n/a n/a n/a
2025-11-14 2025-09-30 13F COSTAR GROUP COM Put 30,600 146.77 2,582 159.14 n/a n/a n/a
2025-08-13 2025-06-30 13F COSTAR GROUP COM Put 12,400 -32.61 997 -31.64 n/a n/a n/a
2025-05-14 2025-03-31 13F COSTAR GROUP COM Put 18,400 -49.73 1,458 -44.39 n/a n/a n/a
2025-02-13 2024-12-31 13F COSTAR GROUP COM Put 36,600 -40.20 2,620 -43.24 n/a n/a n/a
2024-11-14 2024-09-30 13F COSTAR GROUP COM Put 61,200 241.90 4,617 247.85 n/a n/a n/a
2024-08-14 2024-06-30 13F COSTAR GROUP COM Put 17,900 -20.80 1,327 -39.21 n/a n/a n/a
2024-05-15 2024-03-31 13F COSTAR GROUP COM Put 22,600 -29.15 2,183 -21.67 n/a n/a n/a
2024-02-14 2023-12-31 13F COSTAR GROUP COM Put 31,900 -34.36 2,788 -25.40 n/a n/a n/a
2023-11-21 2023-09-30 13F/A COSTAR GROUP COM Put 48,600 548.00 3,737 460.12 n/a n/a n/a
2023-11-14 2023-09-30 13F COSTAR GROUP COM Put 48,600 3,737 n/a n/a n/a
2023-08-14 2023-06-30 13F COSTAR GROUP COM Put 7,500 1,150.00 668 1,526.83 n/a n/a n/a
2023-05-15 2023-03-31 13F COSTAR GROUP COM Put 600 -89.29 41 -90.51 n/a n/a n/a
2023-02-14 2022-12-31 13F COSTAR GROUP COM Put 5,600 433 n/a n/a n/a
2020-02-14 2019-12-31 13F COSTAR GROUP COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F COSTAR GROUP COM Put 200 119 n/a n/a n/a
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.