Quest Diagnostics Incorporated
US ˙ NYSE ˙ US74834L1008

SecurityDGX / Quest Diagnostics Incorporated
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership1,949,535 shares
Latest Disclosed Value $ 382,085,386
Dimensional Fund Advisors Lp reports 0.93% increase in ownership of DGX / Quest Diagnostics Incorporated

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 1,949,535 shares of Quest Diagnostics Incorporated (US:DGX) valued at $382,069,869 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 1,931,548 shares of Quest Diagnostics Incorporated. This represents a change in shares of 0.93% during the quarter. The current value of the position is $390,472,365 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)
2026-05-07 2026-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,949,535 17,987 0.93 382,085 13.99 0.0794
2026-02-12 2025-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,931,548 24,038 1.26 335,204 -7.79 0.0703
2025-11-12 2025-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,907,510 6,155 0.32 363,509 6.44 0.0780
2025-08-12 2025-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,901,355 -11,205 -0.59 341,510 5.54 0.0791
2025-05-13 2025-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,912,560 -128,905 -6.31 323,574 5.06 0.0804
2025-02-13 2024-12-31 13F QUEST DIAGNOSTICS COM 74834L100 2,041,465 -5,156 -0.25 307,978 -3.07 0.0740
2024-11-07 2024-09-30 13F QUEST DIAGNOSTICS COM 74834L100 2,046,621 -62,894 -2.98 317,731 10.03 0.0771
2024-08-09 2024-06-30 13F QUEST DIAGNOSTICS COM 74834L100 2,109,515 129,395 6.53 288,758 9.55 0.0754
2024-05-10 2024-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,980,120 7,001 0.35 263,574 -3.12 0.0714
2024-02-07 2023-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,973,119 253 0.01 272,051 13.15 0.0794
2023-11-09 2023-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,972,866 -17,807 -0.89 240,438 -14.07 0.0789
2023-08-09 2023-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,990,673 -30,178 -1.49 279,820 -2.12 0.0892
2023-05-12 2023-03-31 13F QUEST DIAGNOSTICS COM 74834L100 2,020,851 -15,416 -0.76 285,881 89,799.69 0.0963
2023-02-09 2022-12-31 13F QUEST DIAGNOSTICS COM 74834L100 2,036,267 -91,304 -4.29 319 -99.88 0.0941
2022-11-10 2022-09-30 13F QUEST DIAGNOSTICS COM 74834L100 2,127,571 -26,880 -1.25 261,064 -8.90 0.1002
2022-08-12 2022-06-30 13F QUEST DIAGNOSTICS COM 74834L100 2,154,451 -35,687 -1.63 286,566 -4.41 0.1028
2022-05-13 2022-03-31 13F QUEST DIAGNOSTICS COM 74834L100 2,190,138 3,219 0.15 299,779 -20.76 0.0923
2022-02-09 2021-12-31 13F QUEST DIAGNOSTICS COM 74834L100 2,186,919 29,895 1.39 378,329 20.69 0.1144
2021-11-12 2021-09-30 13F QUEST DIAGNOSTICS COM 74834L100 2,157,024 -1,101 -0.05 313,483 10.06 0.1010
2021-08-12 2021-06-30 13F QUEST DIAGNOSTICS COM 74834L100 2,158,125 166,433 8.36 284,823 11.43 0.0902
2021-05-14 2021-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,991,692 64,214 3.33 255,618 11.29 0.0845
2021-03-08 2020-12-31 13F/A-2 QUEST DIAGNOSTICS COM 74834L100 1,927,478 79,856 4.32 229,685 8.59 0.0829
2021-02-11 2020-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,927,478 79,856 229,685 82,950.0136
2020-11-12 2020-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,847,622 -15,127 -0.81 211,512 -0.33 0.0897
2020-08-13 2020-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,862,749 -51,793 -2.71 212,222 38.01 0.0933
2020-05-14 2020-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,914,542 -27,004 -1.39 153,778 -25.83 0.0801
2020-02-14 2019-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,941,546 -21,647 -1.10 207,331 -1.32 0.0756
2019-11-12 2019-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,963,193 -17,323 -0.87 210,099 4.21 0.0816
2019-08-13 2019-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,980,516 -24,593 -1.23 201,619 11.83 0.0783
2019-08-12 2019-03-31 13F/A-2 QUEST DIAGNOSTICS COM 74834L100 2,005,109 22,748 1.15 180,289 9.23 0.0718
2019-05-10 2019-03-31 13F QUEST DIAGNOSTICS COM 74834L100 2,005,109 22,748 180,289
2019-02-26 2018-12-31 13F/A-1 QUEST DIAGNOSTICS COM 74834L100 1,982,361 9,047 0.46 165,058 -22.48 0.0748
2019-02-13 2018-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,982,361 9,047 165,058
2018-11-13 2018-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,973,314 -20,968 -1.05 212,928 -2.89 0.0811
2018-08-10 2018-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,994,282 -17,086 -0.85 219,258 8.68 0.0874
2018-05-11 2018-03-31 13F QUEST DIAGNOSTICS COM 74834L100 2,011,368 -6,805 -0.34 201,740 1.49 0.0841
2018-02-12 2017-12-31 13F QUEST DIAGNOSTICS COM 74834L100 2,018,173 -11,451 -0.56 198,783 4.61 0.0824
2017-11-13 2017-09-30 13F QUEST DIAGNOSTICS COM 74834L100 2,029,624 4,516 0.22 190,029 -15.58 0.0830
2017-08-11 2017-06-30 13F QUEST DIAGNOSTICS COM 74834L100 2,025,108 3,001 0.15 225,105 13.37 0.1039
2017-05-12 2017-03-31 13F QUEST DIAGNOSTICS COM 74834L100 2,022,107 99,153 5.16 198,551 12.35 0.0949
2017-02-09 2016-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,922,954 39,748 2.11 176,721 10.89 0.0883
2016-11-10 2016-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,883,206 143,070 8.22 159,361 12.50 0.0861
2016-08-09 2016-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,740,136 230,885 15.30 141,648 31.34 0.0815
2016-05-13 2016-03-31 13F QUEST DIAGNOSTICS COM 74834L100 1,509,251 63,133 4.37 107,847 4.82 0.0646
2016-02-10 2015-12-31 13F QUEST DIAGNOSTICS COM 74834L100 1,446,118 49,332 3.53 102,885 19.83 0.0641
2015-11-13 2015-09-30 13F QUEST DIAGNOSTICS COM 74834L100 1,396,786 203,375 17.04 85,858 -0.78 0.0564
2015-08-14 2015-06-30 13F QUEST DIAGNOSTICS COM 74834L100 1,193,411 284,263 31.27 86,535 23.85 0.0530
2015-05-14 2015-03-31 13F QUEST DIAGNOSTICS COM 74834L100 909,148 62,217 7.35 69,872 23.00 0.0441
2015-02-06 2014-12-31 13F QUEST DIAGNOSTICS COM 74834L100 846,931 284,239 50.51 56,807 66.33 0.0373
2014-11-13 2014-09-30 13F QUEST DIAGNOSTICS COM 74834L100 562,692 9,344 1.69 34,154 5.16 0.0242
2014-08-08 2014-06-30 13F QUEST DIAGNOSTICS COM 74834L100 553,348 115,113 26.27 32,477 27.95 0.0226
2014-05-14 2014-03-31 13F QUEST DIAGNOSTICS COM 74834L100 438,235 40,386 10.15 25,383 19.14 0.0190
2014-02-12 2013-12-31 13F QUEST DIAGNOSTICS COM 74834L100 397,849 -1,916 -0.48 21,305 -13.74 0.0166
2013-11-13 2013-09-30 13F QUEST DIAGNOSTICS COM 74834L100 399,765 43,042 12.07 24,699 14.18 0.0214
2013-08-15 2013-06-30 13F QUEST DIAGNOSTICS COM 74834L100 356,723 356,723 21,631 0.0204
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.