What if you'd held INSP?
A $1,000 investment in Inspire Medical Systems, Inc. (INSP) at the month-end close of 2018-05 would be worth $2,056 at the close of 2026-08 — +105.6% total return, dividends reinvested. The same $1,000 in the S&P 500 would be worth $2,849.
Your scenario
Result
If you'd bought $1,000 at the start of each year
Value of $1,000 invested on January 1 of each year, held to 2026-08, dividends included.
Every year, $1,000 from 2018
| Year | Value of $1,000 | Year return |
|---|---|---|
| 2018 | $1,000 | — |
| 2019 | $1,756 | +75.6% |
| 2020 | $4,452 | +153.5% |
| 2021 | $5,445 | +22.3% |
| 2022 | $5,962 | +9.5% |
| 2023 | $4,815 | -19.2% |
| 2024 | $4,388 | -8.9% |
| 2025 | $2,183 | -50.2% |
| 2026 | $1,460 | -33.1% |
Best and worst month-end to buy
The best single month-end close to have bought INSP was 2018-05 ($30.00): $1,000 then is $2,056 today. The worst was 2023-06 ($325): $1,000 then is $190.
FAQ
What would $1,000 in INSP be worth today?
A $1,000 investment in Inspire Medical Systems, Inc. (INSP) at the start of 2018 would be worth about $2,056 today, a total return of +105.6%. Dividends are reinvested in these figures.
What were the best and worst years for INSP?
Inspire Medical Systems, Inc. (INSP)'s strongest calendar year since 2018 was 2020, a +153.5% return — $1,000 held through that year became about $2,535 by year-end. Its weakest year was 2025, at -50.2%.
Does the calculator include dividends and splits?
Yes where available. Prices are adjusted for both stock splits and reinvested dividends (total return), the same measure brokerages use.
How much would $100 per month in INSP have grown?
Investing $100 at the end of every month since 2018-05 would have grown to about $6,171 on $10,000 invested.
Did INSP beat the S&P 500?
Over the same period, $1,000 in the S&P 500 index would be worth $2,849. INSP trailed the S&P 500 by +27.8% in total return.
Is this investment advice?
No. Wall Street Regrets is an entertainment and education tool. Every number is a historical calculation, not a prediction, and past performance never guarantees future results.
Methodology
Inspire Medical Systems, Inc. (INSP) historical total-return data from 2018-05 to 2026-08, reduced to month-end closes for the tables above.
Returns use adjusted close prices from Yahoo Finance historical data — adjusted for stock splits and reinvested dividends — the same convention used by major brokerages. A "year" scenario invests $1,000 at the prior December's month-end close and values it at the latest available month-end close. Non-USD amounts are converted at historical month-end exchange rates (Yahoo Finance): to USD on the buy date and back to your currency at the latest rate, so the return reflects the currency move as well as the asset.
Month-end resolution means intra-month extremes are not captured in tables; the calculator uses exact trading-day closes where daily data is available. Figures ignore taxes, fees, and the currency effects of non-USD listings. History is not a forecast. Wall Street Regrets is entertainment, not investment advice.
What if you'd held…
Data: adjusted close prices via Yahoo Finance. As of 2026-08. Not financial advice.