What if you'd held ICLR?
A $1,000 investment in ICON plc (ICLR) at the month-end close of 1998-05 would be worth $26,649 at the close of 2026-08 — +2564.9% total return, dividends reinvested. The same $1,000 in the S&P 500, dividends reinvested, would be worth $11,719.
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 1998
| Year | Value of $1,000 | Year return |
|---|---|---|
| 1998 | $1,000 | — |
| 1999 | $507 | -49.3% |
| 2000 | $511 | +0.7% |
| 2001 | $889 | +74.1% |
| 2002 | $803 | -9.7% |
| 2003 | $1,301 | +62.0% |
| 2004 | $1,146 | -11.9% |
| 2005 | $1,227 | +7.1% |
| 2006 | $2,249 | +83.4% |
| 2007 | $3,691 | +64.1% |
| 2008 | $2,350 | -36.3% |
| 2009 | $2,593 | +10.4% |
| 2010 | $2,613 | +0.8% |
| 2011 | $2,042 | -21.9% |
| 2012 | $3,313 | +62.2% |
| 2013 | $4,823 | +45.6% |
| 2014 | $6,085 | +26.2% |
| 2015 | $9,272 | +52.4% |
| 2016 | $8,974 | -3.2% |
| 2017 | $13,383 | +49.1% |
| 2018 | $15,419 | +15.2% |
| 2019 | $20,553 | +33.3% |
| 2020 | $23,267 | +13.2% |
| 2021 | $36,957 | +58.8% |
| 2022 | $23,180 | -37.3% |
| 2023 | $33,779 | +45.7% |
| 2024 | $25,025 | -25.9% |
| 2025 | $21,745 | -13.1% |
| 2026 | $20,289 | -6.7% |
Best and worst month-end to buy
The best single month-end close to have bought ICLR was 1999-05 ($3.13): $1,000 then is $54,319 today. The worst was 2024-03 ($336): $1,000 then is $506.
FAQ
What would $1,000 in ICLR be worth today?
A $1,000 investment in ICON plc (ICLR) at the start of 1998 would be worth about $26,649 today, a total return of +2564.9%. Dividends are reinvested in these figures.
What were the best and worst years for ICLR?
ICON plc (ICLR)'s strongest calendar year since 1998 was 2006, a +83.4% return — $1,000 held through that year became about $1,834 by year-end. Its weakest year was 1999, at -49.3%.
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 ICLR have grown?
Investing $100 at the end of every month since 1998-05 would have grown to about $340,938 on $34,000 invested.
Did ICLR beat the S&P 500?
Over the same period, $1,000 in the S&P 500 with dividends reinvested (the S&P 500 Total Return index) would be worth $11,719. ICLR beat the S&P 500 by +127.4% 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
ICON plc (ICLR) historical total-return data from 1998-05 to 2026-08, reduced to month-end closes for the tables above.
Returns use adjusted close prices — adjusted for stock splits and reinvested dividends, the same convention used by major brokerages. End-of-day and live prices come from EODHD; parts of the deep historical series are carried over from Yahoo Finance data. 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 (EODHD): 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 EODHD and Yahoo Finance. As of 2026-08. Not financial advice.