Quest Diagnostics Incorporated
US ˙ NYSE ˙ US74834L1008

SecurityDGX / Quest Diagnostics Incorporated
InstitutionParallel Advisors, LLC
Latest Disclosed Ownership3,383 shares
Latest Disclosed Value $ 587,188
Parallel Advisors, LLC ownership in DGX / Quest Diagnostics Incorporated

On February 11, 2026 - Parallel Advisors, LLC filed a 13F-HR form disclosing ownership of 3,383 shares of Quest Diagnostics Incorporated (US:DGX) valued at $587,052 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 3,362 shares of Quest Diagnostics Incorporated. This represents a change in shares of 0.62% during the quarter. The current value of the position is $655,186 USD.

Parallel Advisors, LLC has a history of taking positions in derivatives of the underlying security (DGX) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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.

DGX / Quest Diagnostics Incorporated 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)
2026-02-11 2025-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,383 21 0.62 587 -8.28 0.0107
2025-11-13 2025-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 3,362 -22 -0.65 641 5.44 0.0117
2025-07-08 2025-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 3,384 100 3.05 608 9.37 0.0121
2025-04-08 2025-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,284 -226 -6.44 556 4.91 0.0125
2025-02-10 2024-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,510 158 4.71 530 1.73 0.0119
2024-11-13 2024-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 3,352 148 4.62 520 18.72 0.0122
2024-08-08 2024-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 3,204 -144 -4.30 439 -1.57 0.0112
2024-05-06 2024-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,348 -547 -14.04 446 -16.98 0.0121
2024-02-12 2023-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,895 -201 -4.91 537 7.41 0.0159
2024-05-20 2023-09-30 13F/A-1 QUEST DIAGNOSTICS Stock 74834L100 4,096 -166 -3.89 499 -16.69 0.0166
2023-11-14 2023-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,096 -166 499 0.0166
2024-05-20 2023-06-30 13F/A-1 QUEST DIAGNOSTICS Stock 74834L100 4,262 -118 -2.69 599 -3.23 0.0193
2023-08-04 2023-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,262 -118 599 0.0193
2024-05-20 2023-03-31 13F/A-1 QUEST DIAGNOSTICS Stock 74834L100 4,380 -45 -1.02 620 -10.55 0.0209
2023-04-25 2023-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,380 -45 620 0.0209
2023-02-06 2022-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,425 267 6.42 692 35.69 0.0300
2022-11-10 2022-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,158 -52 -1.24 510 -8.93 0.0235
2022-08-01 2022-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,210 -6 -0.14 560 -4.44 0.0257
2022-04-28 2022-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,216 -546 -11.47 586 -28.88 0.0233
2022-01-20 2021-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,762 -351 -6.86 824 10.90 0.0306
2021-11-02 2021-09-30 13F/A-1 QUEST DIAGNOSTICS Stock 74834L100 5,113 772 17.78 743 29.67 0.0300
2021-08-06 2021-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,341 66 1.54 573 4.37 0.0243
2021-04-23 2021-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,275 84 2.00 549 10.02 0.0259
2021-02-02 2020-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 4,191 -22 -0.52 499 3.53 0.0271
2020-10-27 2020-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,213 -315 -6.96 482 -6.59 0.0298
2020-07-16 2020-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 4,528 634 16.28 516 65.38 0.0337
2020-04-27 2020-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 3,894 2,873 281.39 312 186.24 0.0253
2020-01-30 2019-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 1,021 -91 -8.18 109 -8.40 0.0082
2019-11-01 2019-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 1,112 6 0.54 119 5.31 0.0102
2019-08-05 2019-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 1,106 -17 -1.51 113 11.88 0.0110
2019-05-01 2019-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 1,123 -26 -2.26 101 6.32 0.0113
2019-02-05 2018-12-31 13F QUEST DIAGNOSTICS Stock 74834L100 1,149 16 1.41 95 -22.13 0.0132
2018-11-01 2018-09-30 13F QUEST DIAGNOSTICS Stock 74834L100 1,133 0 0.00 122 -1.61 0.0152
2018-07-30 2018-06-30 13F QUEST DIAGNOSTICS Stock 74834L100 1,133 2 0.18 124 9.73 0.0177
2018-05-08 2018-03-31 13F QUEST DIAGNOSTICS Stock 74834L100 1,131 -84 -6.91 113 -5.83 0.0176
2018-02-13 2017-12-31 13F QUEST DIAGNOSTICS INC COM Stock 74834L100 1,215 38 3.23 120 11.11 0.0196
2017-11-15 2017-09-30 13F/A-1 QUEST DIAGNOSTICS INC COM Stock 74834L100 1,177 -114 -8.83 108 -22.86 0.0186
2017-08-07 2017-06-30 13F QUEST DIAGNOSTICS INC COM Stock 74834L100 1,291 12 0.94 140 2.19 0.0264
2017-05-12 2017-03-31 13F/A-1 QUEST DIAGNOSTICS INC COM Stock 74834L100 1,279 177 16.06 137 35.64 0.0272
2017-05-12 2017-03-31 13F QUEST DIAGNOSTICS INC COM Stock 74834L100 1,279 137
2017-02-14 2016-12-31 13F QUEST DIAGNOSTICS INC COM Stock 74834L100 1,102 1,102 101 0.0237
Disclosed Call 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
(%)
2022-01-19 2021-12-31 13F QUEST DIAGNOSTICS Stock Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-10-22 2021-09-30 13F QUEST DIAGNOSTICS Stock Call 4,341 573 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.