NYSE: DGX · Diagnostics & Research
Quest Diagnostics (DGX) fair value: undervalued or overvalued?
As of 3 Oct 2026, Faircurve's model values Quest Diagnostics (DGX) at $277.32 a share. The stock last closed at $233.33, which puts the model's fair value 18.9% above the price. On the model's bands that reads as Undervalued.
Revalued . Price is the close of 2 Oct 2026. Quest Diagnostics Incorporated.
Faircurve Insights · 3 Oct 2026
Quest Diagnostics Incorporated was founded in 1967 and is headquartered in Secaucus, New Jersey. It is a premier provider of diagnostic testing, information, and related services, serving clients both domestically and internationally.
On 3 Oct 2026, Faircurve's model found a fair value of $277.32 a share, the midpoint of 2,000 simulations. The previous run on 26 Sep 2026 gave $280.88, so the fair value moved -1.3%. The calibrated range over 63 trading days is $231.37 to $336.20, built from the fair value and calibrated weekly against realised prices, which held the price 60% of the time at this horizon. The evidence grade is Medium.
The overall quality score for the business is 68 out of 100 against comparable companies. The model compares it with Mettler-Toledo International Inc., Revvity, Inc., Medpace Holdings, Inc., IDEXX Laboratories, Inc., Illumina, Inc., Waters Corporation, and IQVIA Holdings Inc. The stock moved around its last 8 earnings reports, measured from the close before each report to the close after it, with a median size, ignoring direction, of 5.8%.
Written from the figures on this page for the 3 Oct 2026 valuation and checked by rule before publishing: every number is one printed here, no forecast, no instruction. The price, the gap and the verdict are the page's own and change daily. Not a recommendation.
What price range does the model give DGX?
The calibrated range for DGX over 63 trading days is $231.37 to $336.20. There is no live options data for this stock, so the range is built from the fair value and calibrated weekly against realised prices (n = 4,809 past valuations, refreshed 3 Oct 2026). Ranges built this way held the price 60% of the time at this horizon.
The model's own simulated range, from the 20th to the 80th percentile of its runs, is $217.38 to $342.65. In 73% of the simulations the fair value came out above the price the model ran on.
How does DGX score on business quality?
Quest Diagnostics's overall quality score is 68 out of 100. Each factor below is a score against comparable companies, not a percentile of the metric beside it.
| Factor | Score (0 to 100) | Headline measure | Peer median |
|---|---|---|---|
| ProfitabilityReturn on invested capital against the peer group, with a bonus for an improving trend. | 61 | 9.3%ROIC | 6.9% |
| Earnings qualityHow much of reported profit is cash: free cash flow to net income, and the accrual ratio (the share of earnings that is not cash). | 81 | 1.15xFCF / net income | 1.38x |
| Growth qualityTrailing revenue growth, forward growth from consensus, and the direction of analyst estimate revisions. | 70 | 11.8%Revenue growth, trailing | 7.2% |
| Capital disciplineReinvestment efficiency (capital spending per unit of revenue) and net buybacks. | 63 | 2.1%Net buybacks / market value | 1.8% |
| Balance sheetNet debt to EBITDA and interest coverage. | 42 | 2.87xNet debt / EBITDA | 3.12x |
| StabilityDownside volatility of the EBITDA margin over the last five years. | 87 | 1.9 ptsEBITDA margin downside volatility, 5y | 14.7 pts |
How does DGX compare with similar companies?
The companies in diagnostics & research closest to Quest Diagnostics in market value, each on the same model and the same date.
| Company | Last close | Model fair value | Gap | Model verdict |
|---|---|---|---|---|
| LH Labcorp Holdings Inc. | $308.49 | $307.10 | -0.5% | Low evidence grade |
| MTD Mettler-Toledo International Inc. | $1,486.19 | $1,435.21 | -3.4% | Fairly valued |
| RVTY Revvity, Inc. | $151.53 | $149.74 | -1.2% | Fairly valued |
| MEDP Medpace Holdings, Inc. | $599.47 | $647.42 | +8.0% | Fairly valued |
| IDXX IDEXX Laboratories, Inc. | $518.39 | $483.04 | -6.8% | Fairly valued |
| ILMN Illumina, Inc. | $273.04 | $207.94 | -23.8% | Overvalued |
| WAT Waters Corporation | $425.21 | $321.73 | -24.3% | Overvalued |
| IQV IQVIA Holdings Inc. | $258.21 | $342.64 | +32.7% | Undervalued |
All diagnostics & research stocks ranked by gap to fair value
When does DGX report earnings, and how has the stock reacted?
Quest Diagnostics's next earnings report is scheduled for 20 Oct 2026. Companies can move their dates.
Options prices on 2 Oct 2026 imply a move of about 9.1% in either direction through the nearest expiry, about 48 days out, a window that includes the report. That is the size the market is pricing, not a direction.
How DGX moved around its last 8 earnings reports
Each move runs from the last close before the report to the first close after it, so it covers companies that report before the open and after the close. The median size across these 8 reports, ignoring direction, was 5.8%.
| Report date | Two session move |
|---|---|
| 23 Jul 2026 | +8.6% |
| 21 Apr 2026 | +3.9% |
| 10 Feb 2026 | +9.4% |
| 21 Oct 2025 | -4.9% |
| 22 Jul 2025 | +2.4% |
| 22 Apr 2025 | +7.2% |
| 30 Jan 2025 | +4.9% |
| 22 Oct 2024 | +6.6% |
Quest Diagnostics at a glance
Quest Diagnostics Incorporated, founded in 1967 and headquartered in Secaucus, New Jersey, is a premier provider of diagnostic testing, information, and related services, serving clients both domestically and internationally.
- Market value
- $25.7B
- Sector
- Healthcare
- Industry
- Diagnostics & Research
- Revenue expected, next twelve months
- $12.4B
- Consensus revenue growth, next fiscal year
- +8.8%
- Analysts with estimates
- 11
- Beta to the US market
- -0.21
- First valued by Faircurve
- 1 May 2026
How the fair value is worked out: the model prices Quest Diagnostics on the value of the whole business, debt included, against the revenue analysts expect next year (forward EV/Sales), runs 2,000 simulations across its inputs and takes the midpoint. The full method is documented here.
What changed in the latest valuation?
On 26 Sep 2026 the model's fair value for DGX was $280.88. As of 3 Oct 2026 it is $277.32, a change of -1.3%. The model revalues every stock it covers each week, and again after an earnings report.
Questions about Quest Diagnostics's valuation
Is Quest Diagnostics stock undervalued or overvalued?
On Faircurve's model, DGX reads as Undervalued as of 3 Oct 2026. The model's fair value is $277.32 a share against a last close of $233.33, a gap of +18.9%.
What is DGX's fair value?
$277.32 a share as of 3 Oct 2026, the midpoint of 2,000 simulations. The model's own 20th to 80th percentile range is $217.38 to $342.65.
What price range does the model give DGX?
$231.37 to $336.20 over 63 trading days. Ranges built this way held the price 60% of the time across 4,809 past valuations, refreshed 3 Oct 2026.
When does Quest Diagnostics report earnings next?
The next report is scheduled for 20 Oct 2026. Companies can move their dates.
How much has DGX moved on past earnings reports?
Across its last 8 reports the median two session move was 5.8%, ignoring direction. The largest was +9.4% around the report of 10 Feb 2026.
How confident is the model in this valuation?
The model's evidence grade for DGX is medium. The grade looks at how complete the inputs are, how many comparable companies there are and how closely they agree, and how wide the range of outcomes is. It is not a probability that the fair value is right, or that the price reaches it.