What if you'd held TGEN?
A $1,000 investment in Tecogen Inc. (TGEN) at the month-end close of 2014-05 would be worth $405 at the close of 2026-08 — -59.5% total return, dividends reinvested. The same $1,000 in the S&P 500 would be worth $4,007.
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 2014
| Year | Value of $1,000 | Year return |
|---|---|---|
| 2014 | $1,000 | — |
| 2015 | $670 | -33.0% |
| 2016 | $805 | +20.0% |
| 2017 | $517 | -35.7% |
| 2018 | $695 | +34.4% |
| 2019 | $406 | -41.6% |
| 2020 | $234 | -42.5% |
| 2021 | $230 | -1.6% |
| 2022 | $239 | +4.2% |
| 2023 | $155 | -35.2% |
| 2024 | $281 | +80.9% |
| 2025 | $946 | +237.2% |
| 2026 | $644 | -32.0% |
Best and worst month-end to buy
The best single month-end close to have bought TGEN was 2024-02 ($0.65): $1,000 then is $5,169 today. The worst was 2025-10 ($9.98): $1,000 then is $337.
FAQ
What would $1,000 in TGEN be worth today?
A $1,000 investment in Tecogen Inc. (TGEN) at the start of 2014 would be worth about $405 today, a total return of -59.5%. Dividends are reinvested in these figures.
What were the best and worst years for TGEN?
Tecogen Inc. (TGEN)'s strongest calendar year since 2014 was 2025, a +237.2% return — $1,000 held through that year became about $3,372 by year-end. Its weakest year was 2020, at -42.5%.
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 TGEN have grown?
Investing $100 at the end of every month since 2014-05 would have grown to about $26,586 on $14,800 invested.
Did TGEN beat the S&P 500?
Over the same period, $1,000 in the S&P 500 index would be worth $4,007. TGEN trailed the S&P 500 by +89.9% 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
Tecogen Inc. (TGEN) historical total-return data from 2014-05 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.