Wall Street RegretsThe regret calculator.

What if you'd held MKSI?

A $1,000 investment in MKS Inc. (MKSI) at the month-end close of 1999-03 would be worth $25,693 at the close of 2026-08 — +2469.3% total return, dividends reinvested. The same $1,000 in the S&P 500 would be worth $5,992.

$1,000 since 1999$25,693Total return+2469.3%Multiple25.7×CAGR+12.6%

Your scenario

Dates resolve to the nearest month-end close.
Leave empty for "held until today".
Invested at each month-end. Starts on the buy date.

Result

Worth$25,693Gain+$24,693 (+2469.3%)Multiple25.7×CAGR+12.6%

    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.

    2000$9,5172001$22,1732002$12,7192003$20,9212004$11,8522005$18,5262006$19,2092007$15,2222008$17,9592009$23,2342010$19,7612011$14,0312012$12,0702013$12,7252014$10,7112015$8,5782016$8,5572017$5,1032018$3,1802019$4,6132020$2,6842021$1,9492022$1,6752023$3,4152024$2,7852025$2,7252026$1,765

    Every year, $1,000 from 1999

    YearValue of $1,000Year return
    1999$1,000
    2000$429-57.1%
    2001$748+74.3%
    2002$455-39.2%
    2003$803+76.5%
    2004$514-36.0%
    2005$495-3.6%
    2006$625+26.2%
    2007$530-15.2%
    2008$410-22.7%
    2009$482+17.6%
    2010$678+40.8%
    2011$788+16.2%
    2012$748-5.1%
    2013$888+18.8%
    2014$1,109+24.9%
    2015$1,112+0.2%
    2016$1,865+67.7%
    2017$2,993+60.5%
    2018$2,063-31.1%
    2019$3,546+71.9%
    2020$4,883+37.7%
    2021$5,683+16.4%
    2022$2,786-51.0%
    2023$3,417+22.6%
    2024$3,492+2.2%
    2025$5,391+54.4%
    2026$9,517+76.5%

    Best and worst month-end to buy

    The best single month-end close to have bought MKSI was 2002-09 ($8.95): $1,000 then is $31,464 today. The worst was 2026-06 ($445): $1,000 then is $633.

    FAQ

    What would $1,000 in MKSI be worth today?

    A $1,000 investment in MKS Inc. (MKSI) at the start of 1999 would be worth about $25,693 today, a total return of +2469.3%. Dividends are reinvested in these figures.

    What were the best and worst years for MKSI?

    MKS Inc. (MKSI)'s strongest calendar year since 1999 was 2003, a +76.5% return — $1,000 held through that year became about $1,765 by year-end. Its weakest year was 2000, at -57.1%.

    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 MKSI have grown?

    Investing $100 at the end of every month since 1999-03 would have grown to about $354,988 on $33,000 invested.

    Did MKSI beat the S&P 500?

    Over the same period, $1,000 in the S&P 500 index would be worth $5,992. MKSI beat the S&P 500 by +328.8% 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

    MKS Inc. (MKSI) historical total-return data from 1999-03 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.

    Full methodology →

    What if you'd held…

    Data: adjusted close prices via Yahoo Finance. As of 2026-08. Not financial advice.