Quest Diagnostics Incorporated
US ˙ NYSE ˙ US74834L1008

SecurityDGX / Quest Diagnostics Incorporated
InstitutionSei Investments Co
Latest Disclosed Ownership71,563 shares
Latest Disclosed Value $ 12,418,225
Sei Investments Co reports 8.60% decrease in ownership of DGX / Quest Diagnostics Incorporated

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 71,563 shares of Quest Diagnostics Incorporated (US:DGX) valued at $12,418,327 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 78,297 shares of Quest Diagnostics Incorporated. This represents a change in shares of -8.60% during the quarter. The current value of the position is $13,859,606 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)
2026-02-13 2025-12-31 13F QUEST DIAGNOSTICS COM 74834L100 71,563 -6,734 -8.60 12,418 -16.77
2025-11-13 2025-09-30 13F QUEST DIAGNOSTICS COM 74834L100 78,297 166 0.21 14,920 6.28 0.0160
2025-08-14 2025-06-30 13F QUEST DIAGNOSTICS COM 74834L100 78,131 -68,505 -46.72 14,038 -43.42 0.0163
2025-05-14 2025-03-31 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 146,636 -11,690 -7.38 24,811 3.88 0.0319
2025-05-13 2025-03-31 13F QUEST DIAGNOSTICS COM 74834L100 173,494 15,168 27,308 0.0297
2025-02-11 2024-12-31 13F QUEST DIAGNOSTICS COM 74834L100 158,326 -20,255 -11.34 23,885 -13.85 0.0307
2024-11-12 2024-09-30 13F QUEST DIAGNOSTICS COM 74834L100 178,581 -35,598 -16.62 27,726 -5.43 0.0360
2024-08-13 2024-06-30 13F QUEST DIAGNOSTICS COM 74834L100 214,179 -64,926 -23.26 29,316 -21.09 0.0415
2024-05-07 2024-03-31 13F QUEST DIAGNOSTICS COM 74834L100 279,105 33,080 13.45 37,152 9.52 0.0544
2024-02-14 2023-12-31 13F QUEST DIAGNOSTICS COM 74834L100 246,025 1,886 0.77 33,922 14.02 0.0545
2023-11-14 2023-09-30 13F QUEST DIAGNOSTICS COM 74834L100 244,139 17,047 7.51 29,750 -6.80 0.0535
2023-08-11 2023-06-30 13F QUEST DIAGNOSTICS COM 74834L100 227,092 19,256 9.26 31,919 8.55 0.0557
2023-05-12 2023-03-31 13F QUEST DIAGNOSTICS COM 74834L100 207,836 66,026 46.56 29,404 32.55 0.0546
2023-02-10 2022-12-31 13F QUEST DIAGNOSTICS COM 74834L100 141,810 -83,581 -37.08 22,185 -19.78 0.0493
2022-11-14 2022-09-30 13F QUEST DIAGNOSTICS COM 74834L100 225,391 21,482 10.54 27,653 1.95 0.0617
2022-08-15 2022-06-30 13F QUEST DIAGNOSTICS COM 74834L100 203,909 12,861 6.73 27,123 3.66 0.0586
2022-05-13 2022-03-31 13F QUEST DIAGNOSTICS COM 74834L100 191,048 34,364 21.93 26,165 -3.50 0.0526
2022-02-14 2021-12-31 13F QUEST DIAGNOSTICS COM 74834L100 156,684 9,752 6.64 27,114 27.02 0.0509
2021-11-12 2021-09-30 13F QUEST DIAGNOSTICS COM 74834L100 146,932 -12,581 -7.89 21,347 1.38 0.0448
2021-08-06 2021-06-30 13F QUEST DIAGNOSTICS COM 74834L100 159,513 45,396 39.78 21,056 43.86 0.0467
2021-05-12 2021-03-31 13F QUEST DIAGNOSTICS COM 74834L100 114,117 22,858 25.05 14,636 34.57 0.0369
2021-02-08 2020-12-31 13F QUEST DIAGNOSTICS COM 74834L100 91,259 12,076 15.25 10,876 19.94 0.0281
2020-12-04 2020-09-30 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 79,183 -2,879 -3.51 9,068 -3.06 0.0263
2020-11-06 2020-09-30 13F QUEST DIAGNOSTICS COM 74834L100 80,354 -1,708 9,202 22,156.3700
2020-08-17 2020-06-30 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 82,062 -31,672 -27.85 9,354 2.37 0.0290
2020-08-11 2020-06-30 13F QUEST DIAGNOSTICS COM 74834L100 120,120 6,386 12,849 34,853.5964
2020-05-14 2020-03-31 13F QUEST DIAGNOSTICS COM 74834L100 113,734 -19,478 -14.62 9,137 -35.95 0.0336
2020-02-06 2019-12-31 13F QUEST DIAGNOSTICS COM 74834L100 133,212 -107,556 -44.67 14,265 -44.72 0.0426
2019-11-12 2019-09-30 13F QUEST DIAGNOSTICS COM 74834L100 240,768 47,231 24.40 25,805 30.94 0.0660
2019-08-14 2019-06-30 13F QUEST DIAGNOSTICS COM 74834L100 193,537 -48,207 -19.94 19,708 -9.42 0.0644
2019-05-15 2019-03-31 13F QUEST DIAGNOSTICS COM 74834L100 241,744 86,404 55.62 21,758 30.54 0.0731
2019-02-13 2018-12-31 13F QUEST DIAGNOSTICS COM 74834L100 155,340 999 0.65 16,668 0.08 0.0593
2018-11-08 2018-09-30 13F QUEST DIAGNOSTICS COM 74834L100 154,341 -9,570 -5.84 16,654 -7.59 0.0604
2018-08-03 2018-06-30 13F QUEST DIAGNOSTICS COM 74834L100 163,911 -59,418 -26.61 18,021 -19.55 0.0613
2018-05-11 2018-03-31 13F QUEST DIAGNOSTICS COM 74834L100 223,329 14,039 6.71 22,399 8.66 0.0859
2018-02-08 2017-12-31 13F QUEST DIAGNOSTICS COM 74834L100 209,290 6,147 3.03 20,614 8.37 0.0716
2017-11-06 2017-09-30 13F QUEST DIAGNOSTICS COM 74834L100 203,143 38,477 23.37 19,022 3.92 0.0676
2017-07-31 2017-06-30 13F QUEST DIAGNOSTICS COM 74834L100 164,666 -23,683 -12.57 18,304 -1.02 0.0730
2017-05-05 2017-03-31 13F QUEST DIAGNOSTICS COM 74834L100 188,349 -6,328 -3.25 18,493 3.36 0.0810
2017-02-02 2016-12-31 13F QUEST DIAGNOSTICS COM 74834L100 194,677 -63,723 -24.66 17,891 -18.19 0.0866
2016-11-04 2016-09-30 13F QUEST DIAGNOSTICS COM 74834L100 258,400 -115,881 -30.96 21,869 -28.23 0.1111
2016-08-11 2016-06-30 13F QUEST DIAGNOSTICS COM 74834L100 374,281 27,087 7.80 30,470 22.83 0.1827
2016-05-10 2016-03-31 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 347,194 -51,817 -12.99 24,807 -12.61 0.1544
2016-02-03 2015-12-31 13F QUEST DIAGNOSTICS COM 74834L100 399,011 56,517 16.50 28,385 34.83 0.1730
2015-11-02 2015-09-30 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 342,494 86,725 33.91 21,052 13.49 0.1932
2015-10-30 2015-09-30 13F DIREXION SHS ETF TR COM 74834L100 342,494 21,054
2015-08-07 2015-06-30 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 255,769 4,377 1.74 18,549 -4.01 0.1677
2015-08-04 2015-06-30 13F QUEST DIAGNOSTICS COM 74834L100 255,769 4,377 18,549 0.1677
2015-05-14 2015-03-31 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 251,392 -19,051 -7.04 19,324 6.56 0.1678
2015-05-01 2015-03-31 13F QUEST DIAGNOSTICS COM 74834L100 251,392 19,324
2015-02-10 2014-12-31 13F QUEST DIAGNOSTICS COM 74834L100 270,443 270,443 18,134 0.1603
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.