科斯公司
US ˙ NasdaqCM ˙ US5006921085

SecurityKOSS / Koss Corporation
InstitutionVanguard Group Inc
Latest Disclosed Ownership222,991 shares
Latest Disclosed Value $ 923,183
Vanguard Group Inc reports 9.25% decrease in ownership of KOSS / Koss Corporation

On January 29, 2026 - Vanguard Group Inc filed a 13F-HR form disclosing ownership of 222,991 shares of Koss Corporation (US:KOSS) valued at $923,183 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 7, 2025 disclosing 245,710 shares of Koss Corporation. This represents a change in shares of -9.25% during the quarter. The current value of the position is $905,343 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)
2026-01-29 2025-12-31 13F KOSS COM 500692108 222,991 -22,719 -9.25 923 -26.04 0.0000
2025-11-07 2025-09-30 13F KOSS COM 500692108 245,710 -802 -0.33 1,248 -0.72 0.0000
2025-08-11 2025-06-30 13F KOSS COM 500692108 246,512 -6,237 -2.47 1,257 5.45 0.0000
2025-05-09 2025-03-31 13F KOSS COM 500692108 252,749 1,808 0.72 1,193 -35.60 0.0000
2025-02-11 2024-12-31 13F KOSS COM 500692108 250,941 0 0.00 1,852 -0.16 0.0000
2024-11-13 2024-09-30 13F KOSS COM 500692108 250,941 -11,565 -4.41 1,854 58.73 0.0000
2024-08-13 2024-06-30 13F KOSS COM 500692108 262,506 0 0.00 1,168 73.29 0.0000
2024-05-10 2024-03-31 13F KOSS COM 500692108 262,506 0 0.00 675 -23.32 0.0000
2024-03-11 2023-12-31 13F/A-1 KOSS COM 500692108 262,506 3,485 1.35 879 14.60 0.0000
2024-02-14 2023-12-31 13F KOSS COM 500692108 262,506 3,485 879 0.0000
2023-12-18 2023-09-30 13F/A-1 KOSS COM 500692108 259,021 7,408 2.94 767 -17.53 0.0000
2023-11-14 2023-09-30 13F KOSS COM 500692108 259,021 7,408 767 0.0000
2023-08-14 2023-06-30 13F KOSS COM 500692108 251,613 448 0.18 931 -19.83 0.0000
2023-07-14 2023-03-31 13F/A-1 KOSS COM 500692108 251,165 19,969 8.64 1,160 1.40 0.0000
2023-05-15 2023-03-31 13F KOSS COM 500692108 251,165 19,969 1,160 0.0000
2023-02-10 2022-12-31 13F KOSS COM 500692108 231,196 152 0.07 1,144 -22.02 0.0000
2022-11-14 2022-09-30 13F KOSS COM 500692108 231,044 6,651 2.96 1,467 -5.90 0.0000
2022-08-12 2022-06-30 13F KOSS COM 500692108 224,393 0 0.00 1,559 -24.17 0.0000
2022-05-13 2022-03-31 13F KOSS COM 500692108 224,393 40,462 22.00 2,056 4.63 0.0000
2022-02-14 2021-12-31 13F KOSS COM 500692108 183,931 18,841 11.41 1,965 -27.20 0.0000
2021-11-12 2021-09-30 13F KOSS COM 500692108 165,090 912 0.56 2,699 -29.20 0.0001
2021-08-13 2021-06-30 13F KOSS COM 500692108 164,178 117,089 248.65 3,812 259.96 0.0001
2021-05-14 2021-03-31 13F KOSS COM 500692108 47,089 47,089 -71.32 1,059 -72.22 0.0000
2020-08-14 2020-06-30 13F KOSS COM 500692108 0 -22,362 -100.00 0 -100.00
2020-05-15 2020-03-31 13F KOSS COM 500692108 22,362 0 0.00 20 -41.18 0.0000
2020-02-14 2019-12-31 13F KOSS COM 500692108 22,362 0 0.00 34 -24.44 0.0000
2019-11-14 2019-09-30 13F KOSS COM 500692108 22,362 0 0.00 45 0.00 0.0000
2019-08-14 2019-06-30 13F KOSS COM 500692108 22,362 0 0.00 45 -2.17 0.0000
2019-05-15 2019-03-31 13F KOSS COM 500692108 22,362 237 1.07 46 9.52 0.0000
2019-02-14 2018-12-31 13F KOSS COM 500692108 22,125 0 0.00 42 -32.26 0.0000
2018-12-13 2018-09-30 13F/A-2 KOSS COM 500692108 22,125 0 0.00 62 19.23 0.0000
2018-11-23 2018-09-30 13F/A-1 KOSS COM 500692108 22,125 0 62 0.0000
2018-11-14 2018-09-30 13F KOSS COM 500692108 22,125 0 62
2018-08-14 2018-06-30 13F KOSS COM 500692108 22,125 0 0.00 52 33.33 0.0000
2018-05-15 2018-03-31 13F KOSS COM 500692108 22,125 6,061 37.73 39 -22.00 0.0000
2018-02-14 2017-12-31 13F KOSS COM 500692108 16,064 0 0.00 50 108.33 0.0000
2017-11-14 2017-09-30 13F KOSS COM 500692108 16,064 0 0.00 24 -20.00 0.0000
2017-08-24 2017-06-30 13F/A-1 KOSS COM 500692108 16,064 0 0.00 30 -11.76 0.0000
2017-08-11 2017-06-30 13F KOSS COM 500692108 16,064 0 30
2017-05-12 2017-03-31 13F KOSS COM 500692108 16,064 0 0.00 34 -8.11 0.0000
2017-02-14 2016-12-31 13F KOSS COM 500692108 16,064 0 0.00 37 5.71 0.0000
2016-11-14 2016-09-30 13F KOSS COM 500692108 16,064 0 0.00 35 6.06 0.0000
2016-08-10 2016-06-30 13F KOSS COM 500692108 16,064 0 0.00 33 -2.94 0.0000
2016-05-13 2016-03-31 13F KOSS COM 500692108 16,064 0 0.00 34 9.68 0.0000
2016-02-08 2015-12-31 13F KOSS COM 500692108 16,064 0 0.00 31 -16.22 0.0000
2015-11-12 2015-09-30 13F/A-1 KOSS COM 500692108 16,064 -241 -1.48 37 -2.63 0.0000
2015-11-12 2015-09-30 13F/A-1 KOSS COM 500692108 16,064 -241 37 0.0000
2015-11-12 2015-09-30 13F KOSS COM 500692108 16,064 37
2015-08-13 2015-06-30 13F KOSS COM 500692108 16,305 3,992 32.42 38 26.67 0.0000
2015-05-15 2015-03-31 13F/A-1 KOSS COM 500692108 12,313 0 0.00 30 36.36 0.0000
2015-05-14 2015-03-31 13F KOSS COM 500692108 12,313 30
2015-02-12 2014-12-31 13F KOSS COM 500692108 12,313 -3,800 -23.58 22 -33.33 0.0000
2014-11-12 2014-09-30 13F KOSS COM 500692108 16,113 -200 -1.23 33 -36.54 0.0000
2014-08-11 2014-06-30 13F KOSS COM 500692108 16,313 16,313 52 0.0000
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.