Does MKS Instruments (MKSI) stock go up or down depending on the month?
MKS Instruments month by month, year by year
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +47.3% | +3.8% | -6.0% | +23.5% | +14.3% | +37.2% | -33.1% | |||||
| 2025 | +8.5% | -18.9% | -12.7% | -12.5% | +17.2% | +20.9% | -4.2% | +8.6% | +19.8% | +16.1% | +8.8% | +2.2% |
| 2024 | +3.5% | +15.3% | +8.3% | -10.5% | +6.4% | +3.2% | -3.6% | -5.3% | -8.8% | -8.6% | +14.4% | -8.1% |
| 2023 | +20.8% | -5.3% | -8.6% | -5.4% | +16.0% | +11.1% | +1.0% | -8.2% | -13.7% | -24.1% | +25.7% | +24.6% |
| 2022 | -10.8% | -3.0% | -0.4% | -24.0% | +8.4% | -16.9% | +15.2% | -15.7% | -17.0% | -0.6% | +2.1% | +1.0% |
| 2021 | +5.1% | +4.3% | +12.4% | -3.4% | +5.1% | -5.5% | -12.1% | -5.9% | +2.5% | -0.6% | +1.4% | +14.5% |
| 2020 | -4.7% | -4.4% | -18.7% | +23.1% | +5.4% | +7.2% | +12.5% | -6.2% | -8.6% | -0.8% | +27.3% | +9.0% |
| 2019 | +26.3% | +1.5% | +12.3% | -2.2% | -21.5% | +9.0% | +9.3% | -8.0% | +17.9% | +17.3% | -1.8% | +3.5% |
| 2018 | +8.3% | +8.8% | +3.9% | -11.5% | +9.6% | -14.7% | -1.5% | -1.5% | -13.7% | -8.1% | +6.5% | -17.7% |
| 2017 | +10.9% | -0.5% | +4.8% | +13.8% | +4.5% | -17.7% | +24.3% | -1.6% | +14.7% | +15.0% | -13.2% | +0.2% |
| 2016 | -1.6% | -7.2% | +14.4% | -4.8% | +14.3% | +5.1% | +6.1% | +6.7% | +2.0% | +1.4% | +14.1% | +3.2% |
| 2015 | -4.3% | +1.0% | -4.4% | +3.0% | +8.3% | +0.6% | -6.4% | -5.1% | -0.5% | +5.1% | +4.6% | -2.4% |
| 2014 | +0.7% | -0.2% | -0.6% | -5.8% | +2.5% | +8.3% | +1.7% | +6.8% | -1.6% | +9.0% | +0.1% | +0.4% |
| 2013 | -2.4% | +0.2% | -1.2% | +4.8% | -5.7% | +2.2% | -7.6% | +6.1% | +11.5% | +0.4% | +0.5% | |
| Average | +8.5% | -0.5% | +0.4% | -1.3% | +6.8% | +3.0% | +0.8% | -3.3% | -0.1% | +2.5% | +7.0% | +2.4% |
| % of years up | 69% | 43% | 50% | 29% | 93% | 64% | 57% | 23% | 46% | 54% | 85% | 77% |
| Years observed | 13 | 14 | 14 | 14 | 14 | 14 | 14 | 13 | 13 | 13 | 13 | 13 |
MKS Instruments month by month: the summary
Over 2013-2026, here's what MKS Instruments (MKSI) stock did each month, on average: January +8.5% (up 69% of 13 years), February -0.5% (up 43% of 14 years), March +0.4% (up 50% of 14 years), April -1.3% (up 29% of 14 years), May +6.8% (up 93% of 14 years), June +3.0% (up 64% of 14 years), July +0.8% (up 57% of 14 years), August -3.3% (up 23% of 13 years), September -0.1% (up 46% of 13 years), October +2.5% (up 54% of 13 years), November +7.0% (up 85% of 13 years), December +2.4% (up 77% of 13 years). In other words, MKSI historically rose in January, March, May, June, July, October, November, December, and fell in February, April, August, September.
Does MKS Instruments really go up in January?
Over 2013-2026, January is MKS Instruments's strongest month: +8.5% on average, positive in 9 of 13 years. At the other end, August shows -3.3%. 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 MKS Instruments stock go up or down in May?
Over 14 years, MKSI rose +6.8% on average in May, finishing the month up 13 times out of 14 (93%). Median: +7.4%. It's one of its most consistent months. ⚠️ 14 years of data is not a prediction.
Does MKS Instruments stock go up or down in November?
Over 13 years, MKSI rose +7.0% on average in November, finishing the month up 11 times out of 13 (85%). Median: +4.6%. It's one of its most consistent months. ⚠️ 13 years of data is not a prediction.
Does MKS Instruments stock go up or down in June?
Over 14 years, MKSI rose +3.0% on average in June, finishing the month up 9 times out of 14 (64%). Median: +4.1%. Results are split year to year — there's no clear pattern. ⚠️ 14 years of data is not a prediction.
Does MKS Instruments stock go up or down in October?
Over 13 years, MKSI rose +2.5% on average in October, finishing the month up 7 times out of 13 (54%). Median: +1.4%. Results are split year to year — there's no clear pattern. ⚠️ 13 years of data is not a prediction.
Does MKS Instruments stock go up or down in December?
Over 13 years, MKSI rose +2.4% on average in December, finishing the month up 10 times out of 13 (77%). Median: +1.0%. It's one of its most consistent months. ⚠️ 13 years of data is not a prediction.
Does MKS Instruments stock go up or down in April?
Over 14 years, MKSI fell -1.3% on average in April, finishing the month up 4 times out of 14 (29%). Median: -4.1%. It's one of its weakest months. ⚠️ 14 years of data is not a prediction.
What is the best month to buy MKS Instruments stock?
Historically, January: over the last 14 years, MKSI gained +8.5% on average that month and finished up 69% of the time (13 years observed). August is the weakest month (-3.3%). This is not a prediction: 14 years is a small sample, and the past is under no obligation to repeat.
Do MKS Instruments's quarterly earnings move the stock?
August — when MKS Instruments reports quarterly earnings — has been its weakest month over 14 years (-3.3% on average, up 23% of years). Earnings are a known driver of moves. ⚠️ This is a past tendency over a short history, not a rule. Use it as context, never as a buy plan.
Why does MKS Instruments stock often rise in January?
January has averaged as its best month over 14 years (+8.5%, 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.
Why is MKS Instruments stock weaker in August?
August has averaged as its weakest month over 14 years (-3.3%, up only 23% of years). This month covers MKS Instruments's quarterly earnings release — a known driver of moves, and over this history it has tended to weigh on the stock.
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 MKSI it's January (+8.5% 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 MKSI, May is the most consistent month (93% 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 MKSI'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.