Quest Diagnostics (DGX) seasonality: returns by month
Quest Diagnostics returns by calendar month since 2000
| Month | Average | Median | Rose in | Best | Worst |
|---|---|---|---|---|---|
| January | −1.1% | −0.4% | 42% of 26 yrs | +16.5% 2004 | −27.1% 2001 |
| February | −0.3% | −0.9% | 41% of 27 yrs | +13.3% 2026 | −10.5% 2021 |
| March | +2.2% | +2.7% | 67% of 27 yrs | +16.8% 2002 | −24.3% 2020 |
| April | +6.6% | +2.0% | 63% of 27 yrs | +46.4% 2000 | −6.6% 2015 |
| May | +2.1% | +1.7% | 70% of 27 yrs | +15.4% 2000 | −7.7% 2010 |
| June | +2.4% | +1.5% | 63% of 27 yrs | +21.1% 2001 | −5.7% 2022 |
| July | +0.7% | −1.6% | 48% of 27 yrs | +35.0% 2000 | −29.8% 2002 |
| August | +0.1% | +0.3% | 56% of 27 yrs | +22.6% 2000 | −12.5% 2020 |
| September | −0.3% | −1.4% | 44% of 27 yrs | +16.3% 2010 | −13.6% 2017 |
| October | −0.4% | −0.2% | 50% of 26 yrs | +17.7% 2022 | −18.5% 2006 |
| November | +3.2% | +4.3% | 85% of 26 yrs | +16.8% 2000 | −12.6% 2002 |
| December | +2.5% | +1.4% | 69% of 26 yrs | +26.4% 2000 | −12.1% 2013 |
Month-end closes adjusted for splits and dividends, through the October 14, 2026 close. Source: Yahoo Finance chart API, monthly close adjusted for splits and dividends. Excludes taxes, fees and inflation. Methodology
Past returns don't repeat. What does the price assume now?
These tables show what already happened. A buyer today gets the next ten years, and the price already reflects what the market expects. The reverse DCF calculator shows the growth today's price implies, so you can judge whether it is realistic.
Frequently asked questions
What is the best month for Quest Diagnostics?
April, with an average return of +6.6% since 2000. It rose in 63% of Aprils (27 years).
What is the worst month for Quest Diagnostics?
January, averaging −1.1% and rising in 42% of years.
Is it a good idea to time purchases by month?
Usually not. Each month has only about 27 observations here, one big year can swing an average, and the gaps between months are small next to a single year's range. Seasonality is a curiosity, not a trading signal.
How are the monthly returns calculated?
Each month's return runs from the previous month-end close to that month's close, using prices adjusted for splits and dividends. The current, unfinished month is left out.
Keep exploring
The math is easy. The macro is hard.
Quest Diagnostics shows the arithmetic. Members get the monthly call that decides which inputs matter, plus written breakpoints when the facts move. $39/month or $249/year.
Members-only research
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