Dorman Products, Inc.
US ˙ NasdaqGS ˙ US2582781009

SecurityDORM / Dorman Products, Inc.
InstitutionAssetmark, Inc
Latest Disclosed Ownership9,967 shares
Latest Disclosed Value $ 1,040,156
Assetmark, Inc reports 12.26% decrease in ownership of DORM / Dorman Products, Inc.

On May 6, 2026 - Assetmark, Inc filed a 13F-HR form disclosing ownership of 9,967 shares of Dorman Products, Inc. (US:DORM) valued at $1,040,156 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 23, 2026 disclosing 11,360 shares of Dorman Products, Inc.. This represents a change in shares of -12.26% during the quarter. The current value of the position is $1,243,383 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)
2026-05-06 2026-03-31 13F DORMAN PRODS COM 258278100 9,967 -1,393 -12.26 1,040 -25.66 0.0021
2026-01-23 2025-12-31 13F DORMAN PRODS COM 258278100 11,360 -1,461 -11.40 1,399 -29.98 0.0029
2025-11-06 2025-09-30 13F DORMAN PRODS COM 258278100 12,821 15 0.12 1,999 27.26 0.0043
2025-08-04 2025-06-30 13F DORMAN PRODS COM 258278100 12,806 -421 -3.18 1,571 -1.51 0.0037
2025-05-06 2025-03-31 13F DORMAN PRODS COM 258278100 13,227 5,159 63.94 1,594 52.54 0.0044
2025-02-06 2024-12-31 13F DORMAN PRODS COM 258278100 8,068 799 10.99 1,045 27.13 0.0028
2024-11-01 2024-09-30 13F DORMAN PRODS COM 258278100 7,269 7,269 822 0.0024
2019-05-14 2019-03-31 13F DORMAN PRODUCTS INC COM COM 258278100 0 -26 -100.00 0 -100.00
2019-02-13 2018-12-31 13F DORMAN PRODUCTS INC COM COM 258278100 26 -91 -77.78 2 -77.78 0.0000
2018-11-13 2018-09-30 13F DORMAN PRODUCTS INC COM COM 258278100 117 6 5.41 9 12.50 0.0001
2018-08-01 2018-06-30 13F DORMAN PRODUCTS INC COM COM 258278100 111 12 12.12 8 14.29 0.0001
2018-05-16 2018-03-31 13F DORMAN PRODUCTS INC COM COM 258278100 99 48 94.12 7 133.33 0.0001
2018-02-13 2017-12-31 13F DORMAN PRODUCTS INC COM COM 258278100 51 -21 -29.17 3 -40.00 0.0000
2017-11-08 2017-09-30 13F DORMAN PRODUCTS INC COM COM 258278100 72 0 0.00 5 -16.67 0.0001
2017-08-14 2017-06-30 13F DORMAN PRODUCTS INC COM COM 258278100 72 0 0.00 6 0.00 0.0001
2017-09-15 2017-03-31 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 72 -10 -12.20 6 0.00 0.0001
2017-05-08 2017-03-31 13F DORMAN PRODUCTS INC COM COM 258278100 72 -10 6
2017-09-15 2016-12-31 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 82 -28 -25.45 6 -14.29 0.0001
2017-02-14 2016-12-31 13F DORMAN PRODUCTS INC COM COM 258278100 82 -28 6
2017-09-14 2016-09-30 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 110 11 11.11 7 16.67 0.0001
2016-11-04 2016-09-30 13F DORMAN PRODUCTS INC COM COM 258278100 110 11 7
2017-09-14 2016-06-30 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 99 0 0.00 6 20.00 0.0001
2016-08-08 2016-06-30 13F DORMAN PRODUCTS INC COM COM 258278100 99 0 6
2017-09-14 2016-03-31 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 99 50 102.04 5 150.00 0.0001
2016-05-13 2016-03-31 13F DORMAN PRODUCTS INC COM COM 258278100 99 50 5
2017-09-14 2015-12-31 13F/A-1 DORMAN PRODUCTS INC COM COM 258278100 49 49 2 0.0000
2016-02-12 2015-12-31 13F DORMAN PRODUCTS INC COM COM 258278100 49 49 2
2015-11-10 2015-09-30 13F DORMAN PRODUCTS INC COM COM 258278100 0 0 0 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.