Wall Street RegretsThe regret calculator.

What if you'd held IONS?

A $1,000 investment in Ionis Pharmaceuticals, Inc. (IONS) at the month-end close of 1991-05 would be worth $6,400 at the close of 2026-08 — +540.0% total return, dividends reinvested. The same $1,000 in the S&P 500 would be worth $19,773.

$1,000 since 1991$6,400Total return+540.0%Multiple6.4×CAGR+5.4%

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$6,400Gain+$5,400 (+540.0%)Multiple6.4×CAGR+5.4%

    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$9,7282001$5,7202002$2,7402003$9,2262004$9,3542005$10,3052006$11,6032007$5,4682008$3,8602009$4,2882010$5,4732011$6,0082012$8,4332013$5,8242014$1,5262015$9852016$9822017$1,2712018$1,2092019$1,1252020$1,0062021$1,0752022$1,9982023$1,6102024$1,2022025$1,7392026$769

    Every year, $1,000 from 1991

    YearValue of $1,000Year return
    1991$1,000
    1992$709-29.1%
    1993$491-30.8%
    1994$291-40.7%
    1995$955+228.3%
    1996$1,309+37.1%
    1997$895-31.6%
    1998$941+5.1%
    1999$455-51.7%
    2000$773+70.1%
    2001$1,614+108.7%
    2002$479-70.3%
    2003$473-1.4%
    2004$429-9.2%
    2005$381-11.2%
    2006$809+112.2%
    2007$1,145+41.6%
    2008$1,031-10.0%
    2009$808-21.7%
    2010$736-8.9%
    2011$524-28.8%
    2012$759+44.8%
    2013$2,897+281.6%
    2014$4,490+55.0%
    2015$4,504+0.3%
    2016$3,479-22.8%
    2017$3,658+5.2%
    2018$3,932+7.5%
    2019$4,393+11.7%
    2020$4,112-6.4%
    2021$2,213-46.2%
    2022$2,747+24.1%
    2023$3,679+33.9%
    2024$2,543-30.9%
    2025$5,753+126.3%
    2026$4,422-23.1%

    Best and worst month-end to buy

    The best single month-end close to have bought IONS was 2005-04 ($2.90): $1,000 then is $20,966 today. The worst was 2025-11 ($82.73): $1,000 then is $735.

    FAQ

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

    A $1,000 investment in Ionis Pharmaceuticals, Inc. (IONS) at the start of 1991 would be worth about $6,400 today, a total return of +540.0%. Dividends are reinvested in these figures.

    What were the best and worst years for IONS?

    Ionis Pharmaceuticals, Inc. (IONS)'s strongest calendar year since 1991 was 2013, a +281.6% return — $1,000 held through that year became about $3,816 by year-end. Its weakest year was 2002, at -70.3%.

    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 IONS have grown?

    Investing $100 at the end of every month since 1991-05 would have grown to about $201,845 on $42,400 invested.

    Did IONS beat the S&P 500?

    Over the same period, $1,000 in the S&P 500 index would be worth $19,773. IONS trailed the S&P 500 by +67.6% 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

    Ionis Pharmaceuticals, Inc. (IONS) historical total-return data from 1991-05 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.

    Full methodology →

    What if you'd held…

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