What if you'd held MPWR?
A $1,000 investment in Monolithic Power Systems, Inc. (MPWR) at the month-end close of 2016-12 would be worth $14,823 at the close on 2026-10-16: a +1382.3% price return. Through September 2026, the latest month the fund has reported, the same $1,000 became $16,457 in MPWR and $3,999 in an S&P 500 index fund (TSP C Fund). The fund figure includes reinvested dividends; the stock figure does not, so the comparison favors the fund.
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 and held to the latest close.
Every year, $1,000 from 2016
| Year | Value of $1,000 | Year return |
|---|---|---|
| 2016 | $1,000 | — |
| 2017 | $1,376 | +37.6% |
| 2018 | $1,421 | +3.3% |
| 2019 | $2,180 | +53.4% |
| 2020 | $4,491 | +106.0% |
| 2021 | $6,046 | +34.6% |
| 2022 | $4,330 | -28.4% |
| 2023 | $7,729 | +78.5% |
| 2024 | $7,246 | -6.3% |
| 2025 | $11,114 | +53.4% |
| 2026 | $14,823 | +33.4% |
Best and worst month to buy
The best month to have bought MPWR was 2016-12, at a close of $81.66: $1,000 then is $14,823 today. The worst was 2026-04, at $1,619: $1,000 then is $748.
FAQ
What would $1,000 in MPWR be worth today?
About $14,823 at the latest close, a price return of +1382.3%. That is $1,000 put into MPWR at the 2016-12 month-end close, the first in this price history.
What were the best and worst years for MPWR?
MPWR's best calendar year since 2016 was 2020, with a +106.0% return: $1,000 invested at the start of that year became about $2,060. Its worst year was 2022, at -28.4%.
Does the calculator include dividends and splits?
Splits only. Price return: adjusted for stock splits, dividends not included. Prices are split-adjusted automatically; a ticker whose history we could not adjust with confidence starts later or is not shown.
How much would $100 per month in MPWR have grown?
To about $58,901 from $11,900 invested, putting in $100 at every monthly close since 2016-12.
Did MPWR beat the S&P 500?
Yes. From the December 2016 month-end through September 2026, MPWR beat an S&P 500 index fund by 311.5%: $1,000 in the fund (the TSP C Fund, dividends included) became $3,999, and $1,000 in MPWR (price only) became $16,457. The fund's monthly returns are published at tsp.gov.
Is this investment advice?
No. Wall Street Regrets is an entertainment and education tool. Every number here is a historical calculation, and past performance never guarantees future results.
Methodology
The figures on this page use MPWR's historical price data from 2016-12 to 2026-10. The tables and the calculator above use month-end closes.
Prices come from IEX Historical Data. A "year" scenario invests $1,000 at the prior December's month-end close and values it at the latest close. Amounts in other currencies are converted at month-end exchange rates published by the European Central Bank and, for earlier years, the Federal Reserve: into US dollars at the buy date's rate and back at the sell date's rate, so the return includes the currency move.
Prices are the last regular-session trade on IEX (Investors Exchange) each day, which can differ slightly from the official close. Month-end closes miss the highs and lows inside a month. Figures ignore taxes, fees and the currency effects of non-USD listings.
What if you'd held…
Prices as of the last IEX trade on 2026-10-16. Data delayed end-of-day.