Dorman Products, Inc.
US ˙ NasdaqGS ˙ US2582781009

SecurityDORM / Dorman Products, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership29,320 shares
Latest Disclosed Value $ 3,612,423
Sei Investments Co ownership in DORM / Dorman Products, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 29,320 shares of Dorman Products, Inc. (US:DORM) valued at $3,611,931 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 22,756 shares of Dorman Products, Inc.. This represents a change in shares of 28.85% during the quarter. The current value of the position is $3,754,133 USD.

Sei Investments Co has a history of taking positions in derivatives of the underlying security (DORM) in the form of stock options.

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 .

Institutional Put/Call Ratios
(Premium Subscription Required)

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.

DORM / Dorman Products, 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)
2026-02-13 2025-12-31 13F DORMAN PRODS COM 258278100 29,320 6,564 28.85 3,612 1.83 0.0036
2025-11-13 2025-09-30 13F DORMAN PRODS COM 258278100 22,756 -3,343 -12.81 3,548 10.81 0.0038
2025-08-14 2025-06-30 13F DORMAN PRODS COM 258278100 26,099 960 3.82 3,202 5.68 0.0037
2025-05-14 2025-03-31 13F/A-1 DORMAN PRODS COM 258278100 25,139 4,252 20.36 3,029 11.90 0.0039
2025-05-13 2025-03-31 13F DORMAN PRODS COM 258278100 19,760 -1,127 2,400 0.0026
2025-02-11 2024-12-31 13F DORMAN PRODS COM 258278100 20,887 9,788 88.19 2,708 115.70 0.0035
2024-11-12 2024-09-30 13F DORMAN PRODS COM 258278100 11,099 2,221 25.02 1,255 54.75 0.0016
2024-08-13 2024-06-30 13F DORMAN PRODS COM 258278100 8,878 190 2.19 812 -3.11 0.0012
2024-05-07 2024-03-31 13F DORMAN PRODS COM 258278100 8,688 221 2.61 837 18.72 0.0012
2024-02-14 2023-12-31 13F DORMAN PRODS COM 258278100 8,467 -74 -0.87 706 9.13 0.0011
2023-11-14 2023-09-30 13F DORMAN PRODS COM 258278100 8,541 122 1.45 647 -2.56 0.0012
2023-08-11 2023-06-30 13F DORMAN PRODS COM 258278100 8,419 -57 -0.67 664 -9.30 0.0012
2023-05-12 2023-03-31 13F DORMAN PRODS COM 258278100 8,476 1,029 13.82 731 21.43 0.0014
2023-02-10 2022-12-31 13F DORMAN PRODS COM 258278100 7,447 880 13.40 603 11.69 0.0013
2022-11-14 2022-09-30 13F DORMAN PRODS COM 258278100 6,567 357 5.75 539 -25.55 0.0012
2022-08-15 2022-06-30 13F DORMAN PRODS COM 258278100 6,210 25 0.40 724 15.10 0.0016
2022-05-13 2022-03-31 13F DORMAN PRODS COM 258278100 6,185 466 8.15 629 -6.12 0.0013
2022-02-14 2021-12-31 13F DORMAN PRODS COM 258278100 5,719 113 2.02 670 17.54 0.0013
2021-11-12 2021-09-30 13F DORMAN PRODS COM 258278100 5,606 1,325 30.95 570 24.73 0.0012
2021-08-06 2021-06-30 13F DORMAN PRODS COM 258278100 4,281 863 25.25 457 42.81 0.0010
2021-05-12 2021-03-31 13F DORMAN PRODS COM 258278100 3,418 0 0.00 320 0.00 0.0008
2021-02-08 2020-12-31 13F DORMAN PRODS COM 258278100 3,418 188 5.82 320 5.26 0.0008
2020-12-04 2020-09-30 13F/A-1 DORMAN PRODUCTS COM 258278100 3,230 189 6.22 304 28.27 0.0009
2020-11-06 2020-09-30 13F DORMAN PRODUCTS COM 258278100 3,305 264 311 748.8189
2020-08-17 2020-06-30 13F/A-1 DORMAN PRODUCTS COM 258278100 3,041 -11,437 -79.00 237 -70.30 0.0007
2020-08-11 2020-06-30 13F DORMAN PRODUCTS COM 258278100 3,041 -11,437 237 642.8751
2020-05-14 2020-03-31 13F DORMAN PRODUCTS COM 258278100 14,478 3,468 31.50 798 -5.79 0.0029
2020-02-06 2019-12-31 13F DORMAN PRODUCTS COM 258278100 11,010 -2,478 -18.37 847 -21.50 0.0025
2019-11-12 2019-09-30 13F DORMAN PRODUCTS COM 258278100 13,488 -1,002 -6.92 1,079 -17.76 0.0028
2019-08-14 2019-06-30 13F DORMAN PRODUCTS COM 258278100 14,490 2,152 17.44 1,312 15.80 0.0043
2019-05-15 2019-03-31 13F DORMAN PRODUCTS COM 258278100 12,338 -4,399 -26.28 1,133 -25.41 0.0038
2019-02-13 2018-12-31 13F DORMAN PRODUCTS COM 258278100 16,737 10,579 171.79 1,519 201.99 0.0054
2018-11-08 2018-09-30 13F DORMAN PRODUCTS COM 258278100 6,158 -12,398 -66.81 503 -60.30 0.0018
2018-08-03 2018-06-30 13F DORMAN PRODUCTS COM 258278100 18,556 70 0.38 1,267 3.43 0.0043
2018-05-11 2018-03-31 13F DORMAN PRODUCTS COM 258278100 18,486 3,814 26.00 1,225 36.57 0.0047
2018-02-08 2017-12-31 13F DORMAN PRODUCTS COM 258278100 14,672 -3,253 -18.15 897 -30.14 0.0031
2017-11-06 2017-09-30 13F DORMAN PRODUCTS COM 258278100 17,925 3,156 21.37 1,284 5.07 0.0046
2017-07-31 2017-06-30 13F DORMAN PRODUCTS COM 258278100 14,769 3,880 35.63 1,222 36.69 0.0049
2017-05-05 2017-03-31 13F DORMAN PRODUCTS COM 258278100 10,889 -1,557 -12.51 894 -1.65 0.0039
2017-02-02 2016-12-31 13F DORMAN PRODUCTS COM 258278100 12,446 -102 -0.81 909 13.48 0.0044
2016-11-04 2016-09-30 13F DORMAN PRODUCTS COM 258278100 12,548 3,139 33.36 801 48.88 0.0041
2016-08-11 2016-06-30 13F DORMAN PRODUCTS COM 258278100 9,409 5,661 151.04 538 163.73 0.0032
2016-05-10 2016-03-31 13F/A-1 DORMAN PRODUCTS COM 258278100 3,748 -10,571 -73.82 204 -70.00 0.0013
2016-02-03 2015-12-31 13F DORMAN PRODUCTS COM 258278100 14,319 3,768 35.71 680 26.63 0.0041
2015-11-02 2015-09-30 13F/A-1 DORMAN PRODUCTS COM 258278100 10,551 2,098 24.82 537 33.25 0.0049
2015-10-30 2015-09-30 13F DORMAN PRODUCTS COM 258278100 10,551 538
2015-08-07 2015-06-30 13F/A-1 DORMAN PRODUCTS COM 258278100 8,453 2,659 45.89 403 40.42 0.0036
2015-08-04 2015-06-30 13F DORMAN PRODUCTS COM 258278100 8,453 2,659 403 0.0036
2015-05-14 2015-03-31 13F/A-1 DORMAN PRODUCTS COM 258278100 5,794 5,614 3,118.89 287 4,000.00 0.0025
2015-05-01 2015-03-31 13F DORCHESTER MINERALS PUT 258278100 5,794 5,794 287 0.0025
2015-02-10 2014-12-31 13F DORMAN PRODUCTS COM 258278100 180 180 7 0.0001
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
(%)
2015-05-01 2015-03-31 13F DORCHESTER MINERALS PUT 5,794 287 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.