Does Merck & Co. (MRK) stock go up or down depending on the month?
Merck & Co. month by month, year by year
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +4.8% | +12.3% | -2.9% | -9.2% | +8.7% | +8.2% | +1.3% | |||||
| 2025 | -0.7% | -6.6% | -2.7% | -5.1% | -9.8% | +3.0% | -1.3% | +7.7% | -0.2% | +2.4% | +21.9% | +0.4% |
| 2024 | +10.8% | +5.3% | +3.8% | -2.1% | -2.8% | -1.4% | -8.6% | +4.7% | -4.1% | -9.9% | -0.7% | -2.1% |
| 2023 | -3.2% | -1.1% | +0.1% | +8.5% | -4.4% | +4.5% | -7.6% | +2.2% | -5.5% | -0.2% | -0.2% | +6.4% |
| 2022 | +6.3% | -6.0% | +7.1% | +8.1% | +3.8% | -0.9% | -2.0% | -4.5% | +0.9% | +17.5% | +8.8% | +0.8% |
| 2021 | -5.8% | -5.8% | +6.2% | -3.4% | +1.9% | +7.4% | -1.2% | -0.8% | -1.5% | +17.2% | -14.9% | +2.3% |
| 2020 | -6.0% | -10.4% | +0.5% | +3.1% | +1.7% | -4.2% | +3.8% | +6.3% | -2.7% | -9.3% | +6.9% | +1.7% |
| 2019 | -2.6% | +9.2% | +2.3% | -5.4% | +0.6% | +5.9% | -1.0% | +4.2% | -2.7% | +3.0% | +0.6% | +4.3% |
| 2018 | +5.3% | -8.5% | +0.5% | +8.1% | +1.1% | +2.0% | +8.5% | +4.1% | +3.4% | +3.8% | +7.8% | -3.7% |
| 2017 | +5.3% | +6.3% | -3.5% | -1.9% | +4.5% | -1.6% | -0.3% | -0.0% | +0.3% | -14.0% | +0.3% | +1.8% |
| 2016 | -4.1% | -0.9% | +5.4% | +3.6% | +2.6% | +2.4% | +1.8% | +7.0% | -0.6% | -5.9% | +4.2% | -3.8% |
| 2015 | +6.1% | -2.9% | -1.8% | +3.6% | +2.2% | -6.5% | +3.6% | -8.7% | -8.3% | +10.7% | -3.0% | -0.4% |
| 2014 | +5.8% | +7.6% | -0.4% | +3.2% | -1.2% | -0.0% | -1.9% | +5.9% | -1.4% | -2.2% | +4.2% | -6.0% |
| 2013 | -1.2% | +3.5% | +6.3% | -0.6% | -0.5% | +3.7% | -1.8% | +0.7% | -5.3% | +10.5% | +0.4% | |
| Average | +1.7% | -0.2% | +1.3% | +1.3% | +0.6% | +1.3% | -0.1% | +2.0% | -1.7% | +0.6% | +3.6% | +0.2% |
| % of years up | 54% | 36% | 64% | 57% | 64% | 50% | 43% | 62% | 31% | 46% | 69% | 62% |
| Years observed | 13 | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 13 |
Merck & Co. month by month: the summary
Over 2013-2026, here's what Merck & Co. (MRK) stock did each month, on average: January +1.7% (up 54% of 13 years), February -0.2% (up 36% of 14 years), March +1.3% (up 64% of 14 years), April +1.3% (up 57% of 14 years), May +0.6% (up 64% of 14 years), June +1.3% (up 50% of 14 years), July -0.1% (up 43% of 14 years), August +2.0% (up 62% of 13 years), September -1.7% (up 31% of 13 years), October +0.6% (up 46% of 13 years), November +3.6% (up 69% of 13 years), December +0.2% (up 62% of 13 years). In other words, MRK historically rose in January, March, April, May, June, August, October, November, December, and fell in February, July, September.
Does Merck & Co. really go up in November?
Over 2013-2026, November is Merck & Co.'s strongest month: +3.6% on average, positive in 9 of 13 years. At the other end, September shows -1.7%. 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 Merck & Co. stock go up or down in August?
Over 13 years, MRK rose +2.0% on average in August, finishing the month up 8 times out of 13 (62%). Median: +4.1%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
Does Merck & Co. stock go up or down in January?
Over 13 years, MRK rose +1.7% on average in January, finishing the month up 7 times out of 13 (54%). Median: +4.8%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
Does Merck & Co. stock go up or down in June?
Over 14 years, MRK rose +1.3% on average in June, finishing the month up 7 times out of 14 (50%). Median: +1.0%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does Merck & Co. stock go up or down in March?
Over 14 years, MRK rose +1.3% on average in March, finishing the month up 9 times out of 14 (64%). Median: +0.5%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does Merck & Co. stock go up or down in April?
Over 14 years, MRK rose +1.3% on average in April, finishing the month up 8 times out of 14 (57%). Median: +3.1%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does Merck & Co. stock go up or down in October?
Over 13 years, MRK rose +0.6% on average in October, finishing the month up 6 times out of 13 (46%). Median: -0.2%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
What is the best month to buy Merck & Co. stock?
Historically, November: over the last 14 years, MRK gained +3.6% on average that month and finished up 69% of the time (13 years observed). September is the weakest month (-1.7%). This is not a prediction: 14 years is a small sample, and the past is under no obligation to repeat.
Why does Merck & Co. stock often rise in November?
November has averaged as its best month over 14 years (+3.6%, 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 MRK it's November (+3.6% 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 MRK, November is the most consistent month (69% 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 MRK'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.