Does Inspire Medical Systems, Inc. (INSP) stock go up or down depending on the month?
Inspire Medical Systems, Inc. month by month, year by year
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | -17.8% | -14.9% | -20.0% | +8.8% | -26.3% | +7.9% | +12.6% | |||||
| 2025 | +4.4% | -4.1% | -14.2% | -0.6% | -12.7% | -6.1% | -4.0% | -24.8% | -20.8% | -2.9% | +72.6% | -25.9% |
| 2024 | +3.7% | -15.1% | +20.0% | +12.5% | -34.3% | -15.7% | +5.4% | +27.5% | +17.4% | -7.6% | -1.2% | -3.8% |
| 2023 | +0.5% | +2.7% | -9.9% | +14.3% | +9.3% | +11.0% | -11.3% | -21.2% | -12.5% | -25.8% | -1.3% | +40.0% |
| 2022 | -3.8% | +10.3% | +5.2% | -19.8% | -14.1% | +3.3% | +14.4% | -8.4% | -7.4% | +9.9% | +23.9% | +4.3% |
| 2021 | +7.1% | +15.5% | -11.1% | +14.4% | -18.0% | -0.5% | -5.2% | +22.1% | +4.2% | +15.8% | -17.2% | +3.0% |
| 2020 | +0.8% | +14.8% | -29.8% | +18.9% | +13.8% | +6.7% | +14.2% | +20.2% | +8.0% | -7.5% | +55.5% | +1.3% |
| 2019 | +26.9% | +15.6% | -8.4% | -9.0% | +9.2% | +7.4% | +11.5% | +2.8% | -12.2% | -0.1% | +16.4% | +4.6% |
| 2018 | +18.9% | +25.6% | +22.7% | -23.5% | -4.8% | +14.6% | -8.0% | |||||
| Average | +2.7% | +3.1% | -8.5% | +5.0% | -9.1% | +3.6% | +7.0% | +5.1% | -5.9% | -2.9% | +20.4% | +1.9% |
| % of years up | 75% | 63% | 25% | 63% | 38% | 67% | 67% | 63% | 38% | 25% | 63% | 63% |
| Years observed | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 8 | 8 | 8 | 8 | 8 |
Inspire Medical Systems, Inc. month by month: the summary
Over 2018-2026, here's what Inspire Medical Systems, Inc. (INSP) stock did each month, on average: January +2.7% (up 75% of 8 years), February +3.1% (up 63% of 8 years), March -8.5% (up 25% of 8 years), April +5.0% (up 63% of 8 years), May -9.1% (up 38% of 8 years), June +3.6% (up 67% of 9 years), July +7.0% (up 67% of 9 years), August +5.1% (up 63% of 8 years), September -5.9% (up 38% of 8 years), October -2.9% (up 25% of 8 years), November +20.4% (up 63% of 8 years), December +1.9% (up 63% of 8 years). In other words, INSP historically rose in January, February, April, June, July, August, November, December, and fell in March, May, September, October.
Does Inspire Medical Systems, Inc. really go up in November?
Over 2018-2026, November is Inspire Medical Systems, Inc.'s strongest month: +20.4% on average, positive in 5 of 8 years. At the other end, May shows -9.1%. 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 Inspire Medical Systems, Inc. stock go up or down in January?
Over 8 years, INSP rose +2.7% on average in January, finishing the month up 6 times out of 8 (75%). Median: +2.2%. It's one of its most consistent months. ⚠️ 8 years of data is not a prediction.
Does Inspire Medical Systems, Inc. stock go up or down in August?
Over 8 years, INSP rose +5.1% on average in August, finishing the month up 5 times out of 8 (63%). Median: +11.5%. Results are split year to year — there's no clear pattern. ⚠️ 8 years of data is not a prediction.
Does Inspire Medical Systems, Inc. stock go up or down in March?
Over 8 years, INSP fell -8.5% on average in March, finishing the month up 2 times out of 8 (25%). Median: -10.5%. It's one of its weakest months. ⚠️ 8 years of data is not a prediction.
Does Inspire Medical Systems, Inc. stock go up or down in July?
Over 9 years, INSP rose +7.0% on average in July, finishing the month up 6 times out of 9 (67%). Median: +11.5%. Results are split year to year — there's no clear pattern. ⚠️ 9 years of data is not a prediction.
Does Inspire Medical Systems, Inc. stock go up or down in September?
Over 8 years, INSP fell -5.9% on average in September, finishing the month up 3 times out of 8 (38%). Median: -9.8%. Results are split year to year — there's no clear pattern. ⚠️ 8 years of data is not a prediction.
Does Inspire Medical Systems, Inc. stock go up or down in April?
Over 8 years, INSP rose +5.0% on average in April, finishing the month up 5 times out of 8 (63%). Median: +10.7%. Results are split year to year — there's no clear pattern. ⚠️ 8 years of data is not a prediction.
What is the best month to buy Inspire Medical Systems, Inc. stock?
Historically, November: over the last 9 years, INSP gained +20.4% on average that month and finished up 63% of the time (8 years observed). May is the weakest month (-9.1%). This is not a prediction: 9 years is a small sample, and the past is under no obligation to repeat.
Why does Inspire Medical Systems, Inc. stock often rise in November?
November has averaged as its best month over 9 years (+20.4%, up 63% of years). No clearly established recurring seasonal driver explains this month — it's a statistical tendency over 9 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 INSP it's November (+20.4% on average over 9 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 INSP, January is the most consistent month (75% positive years). We also rank all 12 months for the whole market.
Does stock seasonality actually work?
Careful. A month that rose 9 times out of 9 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 INSP's real monthly closing prices from 2018 to 2026 (9 years), source Yahoo Finance. Each cell = the price change over that month. Price performance, excluding dividends. Incomplete months and quote gaps are excluded.