Does Dexcom (DXCM) stock go up or down depending on the month?
Dexcom month by month, year by year
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +10.0% | +0.5% | -14.5% | -5.2% | +23.8% | -8.7% | +23.9% | |||||
| 2025 | +11.6% | +1.8% | -22.7% | +4.5% | +20.2% | +1.7% | -7.5% | -6.7% | -10.7% | -13.5% | +9.0% | +4.6% |
| 2024 | -2.2% | -5.2% | +20.5% | -8.2% | -6.8% | -4.5% | -40.2% | +2.2% | -3.3% | +5.1% | +10.7% | -0.3% |
| 2023 | -5.4% | +3.7% | +4.7% | +4.4% | -3.4% | +9.6% | -3.1% | -18.9% | -7.6% | -4.8% | +30.0% | +7.4% |
| 2022 | -19.8% | -3.8% | +23.6% | -20.1% | -27.1% | +0.1% | +10.1% | +0.2% | -2.0% | +50.0% | -3.7% | -2.6% |
| 2021 | +1.4% | +6.1% | -9.6% | +7.4% | -4.3% | +15.6% | +20.7% | +2.7% | +3.3% | +14.0% | -9.7% | -4.6% |
| 2020 | +10.1% | +14.6% | -2.4% | +24.5% | +12.9% | +7.2% | +7.4% | -2.3% | -3.1% | -22.5% | +0.0% | +15.7% |
| 2019 | +17.7% | -1.2% | -14.5% | +1.7% | +0.2% | +23.5% | +4.7% | +9.4% | -13.0% | +3.4% | +47.4% | -3.8% |
| 2018 | +1.4% | -3.6% | +32.1% | -1.3% | +20.2% | +8.0% | +0.1% | +51.8% | -0.9% | -7.2% | -2.4% | -7.6% |
| 2017 | +32.6% | -1.3% | +8.4% | -8.0% | -14.3% | +9.5% | -9.0% | +12.0% | -34.4% | -8.1% | +30.0% | -1.8% |
| 2016 | -13.0% | -8.8% | +4.4% | -5.2% | +0.2% | +23.0% | +16.3% | -1.3% | -3.7% | -10.8% | -16.6% | -8.5% |
| 2015 | +8.6% | +1.7% | +2.6% | +8.3% | +6.2% | +11.5% | +5.8% | +11.2% | -8.8% | -3.0% | +2.0% | -3.6% |
| 2014 | +14.2% | +11.5% | -8.3% | -21.6% | +4.1% | +17.4% | -4.9% | +17.3% | -9.5% | +12.4% | +14.4% | +7.0% |
| 2013 | -2.1% | +12.1% | -1.9% | +27.1% | +7.7% | -2.9% | +24.0% | +4.3% | +1.8% | +15.2% | +7.0% | |
| Average | +5.2% | +1.0% | +2.6% | -1.5% | +4.2% | +8.7% | +1.5% | +7.8% | -6.9% | +1.3% | +9.7% | +0.7% |
| % of years up | 69% | 50% | 57% | 43% | 64% | 86% | 57% | 69% | 15% | 46% | 69% | 38% |
| Years observed | 13 | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 13 |
Dexcom month by month: the summary
Over 2013-2026, here's what Dexcom (DXCM) stock did each month, on average: January +5.2% (up 69% of 13 years), February +1.0% (up 50% of 14 years), March +2.6% (up 57% of 14 years), April -1.5% (up 43% of 14 years), May +4.2% (up 64% of 14 years), June +8.7% (up 86% of 14 years), July +1.5% (up 57% of 14 years), August +7.8% (up 69% of 13 years), September -6.9% (up 15% of 13 years), October +1.3% (up 46% of 13 years), November +9.7% (up 69% of 13 years), December +0.7% (up 38% of 13 years). In other words, DXCM historically rose in January, February, March, May, June, July, August, October, November, December, and fell in April, September.
Does Dexcom really go up in November?
Over 2013-2026, November is Dexcom's strongest month: +9.7% on average, positive in 9 of 13 years. At the other end, September shows -6.9%. But a monthly gap is often built on one or two extreme years — the table above shows it: look at the spread, not just the average. Seasonality only means something when it has a cause (selling season, earnings calendar, year-end tax effects); with no identified cause, it's probably noise.
Frequently asked questions
Does Dexcom stock go up or down in June?
Over 14 years, DXCM rose +8.7% on average in June, finishing the month up 12 times out of 14 (86%). Median: +8.7%. It's one of its most consistent months. ⚠️ 14 years of data is not a prediction.
Does Dexcom stock go up or down in August?
Over 13 years, DXCM rose +7.8% on average in August, finishing the month up 9 times out of 13 (69%). Median: +2.7%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
Does Dexcom stock go up or down in January?
Over 13 years, DXCM rose +5.2% on average in January, finishing the month up 9 times out of 13 (69%). Median: +8.6%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
Does Dexcom stock go up or down in May?
Over 14 years, DXCM rose +4.2% on average in May, finishing the month up 9 times out of 14 (64%). Median: +2.1%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does Dexcom stock go up or down in March?
Over 14 years, DXCM rose +2.6% on average in March, finishing the month up 8 times out of 14 (57%). Median: +3.5%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does Dexcom stock go up or down in July?
Over 14 years, DXCM rose +1.5% on average in July, finishing the month up 8 times out of 14 (57%). Median: +2.4%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
What is the best month to buy Dexcom stock?
Historically, November: over the last 14 years, DXCM gained +9.7% on average that month and finished up 69% of the time (13 years observed). September is the weakest month (-6.9%). This is not a prediction: 14 years is a small sample, and the past is under no obligation to repeat.
Why does Dexcom stock often rise in November?
November has averaged as its best month over 14 years (+9.7%, up 69% of years). No clearly established recurring seasonal driver explains this month — it's a statistical tendency over 14 years of history, not a prediction.
Is there a best month to invest in the stock market in general?
There's no universal rule: every stock has its own seasonality. For DXCM it's November (+9.7% on average over 14 years) — another stock will look completely different. The calendar effects people cite ("sell in May", the year-end rally) are market-wide averages, not laws: on DXCM, June is the most consistent month (86% positive years). We also rank all 12 months for the whole market.
Does stock seasonality actually work?
Careful. A month that rose 14 times out of 14 can simply be chance: with 12 months and a dozen years, patterns appear naturally even in random data. Seasonality describes what happened; it doesn't explain why and predicts nothing. Treat it as context, never as a standalone buy signal.
What data is this table based on?
On DXCM's real monthly closing prices from 2013 to 2026 (14 years), source Yahoo Finance. Each cell = the price change over that month. Price performance, excluding dividends. Incomplete months and quote gaps are excluded.