TGEN (Tecogen) E10: $-0.16 (As of Mar. 2026)


TGEN Tecogen Inc TGEN
50 GF Score
Price $5.38
GF Value $1.18
Valuation Significantly Overvalued
! 3 Warning Signs
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What is Tecogen E10?

Tecogen TGEN -5.94% 50 E10 is $-0.16 as of Mar. 2026. GuruFocus rates TGEN with a GF Score™ of 50/100 and a GF Value™ of $1.18 (Significantly Overvalued). The stock has 3 warning signs investors should review.

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. E10 is the average of the inflation adjusted earnings of a company over the past 10 years.

Tecogen's adjusted earnings per share data for the three months ended in Mar. 2026 was $-0.070. Add all the adjusted EPS for the past 10 years together and divide 10 will get our e10, which is $-0.16 for the trailing ten years ended in Mar. 2026.

Please click Growth Rate Calculation Example (GuruFocus) to see how GuruFocus calculates Wal-Mart Stores Inc (WMT)'s revenue growth rate. You can apply the same method to get the E10 growth rate using E10 data.

During the past 13 years, the highest 3-Year average E10 Growth Rate of Tecogen was 2.30% per year. The lowest was 0.00% per year. And the median was 1.15% per year.

As of today (2026-06-24), Tecogen's current stock price is $5.38. Tecogen's E10 for the quarter that ended in Mar. 2026 was $-0.16. Tecogen's Shiller PE Ratio of today is .


Tecogen  (AMEX:TGEN) E10 Explanation

If a company grows much fast than inflation, E10 may underestimate the company's earnings power. Shiller PE Ratio can seem to be too high even the actual P/E is low.

For the Shiller P/E, the earnings of the past 10 years are inflation-adjusted and averaged. The result is used for P/E calculation. Since it looks at the average over the last 10 years, the Shiller P/E is also called PE10.

The Shiller P/E was first used by professor Robert Shiller to measure the valuation of the overall market. The same calculation is applied here to individual companies.


Be Aware

Shiller PE Ratio works better for cyclical companies. It gives you a better idea on the company's real earnings power.


Tecogen E10 Related Terms


Tecogen E10 Historical Data

* Premium members only.

The historical data trend for Tecogen's E10 can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

Tecogen E10 Chart

Tecogen Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
E10
Get a 7-Day Free Trial Premium Member Only Premium Member Only -0.15 -0.16 -0.15 -0.14 -0.16

Tecogen Quarterly Data
Jun21 Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26
E10 Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only -0.14 -0.15 -0.15 -0.16 -0.16

TGEN vs RFIL, ESP, UTKN: E10 Comparison

For the Electrical Equipment & Parts subindustry, Tecogen's Shiller PE Ratio, along with its competitors' market caps and Shiller PE Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


Tecogen Shiller PE Ratio vs Industrial Products Industry

For the Industrial Products industry and Industrials sector, Tecogen's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where Tecogen's Shiller PE Ratio falls into.


TGEN
50GF Score
Tecogen Inc TGEN
E10 is just one metric. See GF Score™, valuation, warning signs, and more.
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Tecogen E10 Calculation

E10 is a concept invented by Prof. Robert Shiller, who uses E10 for his Shiller P/E calculation. When we calculate the today's Shiller P/E ratio of a stock, we use today's price divided by E10.

What is E10? How do we calculate E10?

E10 is the average of the inflation adjusted earnings of a company over the past 10 years. Let's use an example to explain.

If we want to calculate the E10 of Wal-Mart (WMT) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.

We adjusted the earnings of 2001 earnings data with the total inflation from 2001 through 2010 to the equivalent earnings in 2010. If the total inflation from 2001 to 2010 is 40%, and Wal-Mart earned $1 a share in 2001, then the 2001's equivalent earnings in 2010 is $1.4 a share. If Wal-Mart earns $1 again in 2002, and the total inflation from 2002 through 2010 is 35%, then the equivalent 2002 earnings in 2010 is $1.35. So on and so forth, you get the equivalent earnings of past 10 years. Then you add them together and divided the sum by 10 to get E10.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

For example, Tecogen's adjusted earnings per share data for the three months ended in Mar. 2026 was:

Adj_EPS= Earnings per Share (Diluted) /CPI of Mar. 2026 (Change)*Current CPI (Mar. 2026)
=-0.07/330.2130*330.2130
=-0.070

Current CPI (Mar. 2026) = 330.2130.

Tecogen Quarterly Data

per share eps CPI Adj_EPS
201606 -0.020 241.018 -0.027
201609 0.010 241.428 0.014
201612 0.000 241.432 0.000
201703 0.002 243.801 0.003
201706 -0.010 244.955 -0.013
201709 0.001 246.819 0.001
201712 0.010 246.524 0.013
201803 0.001 249.554 0.001
201806 -0.030 251.989 -0.039
201809 -0.020 252.439 -0.026
201812 -0.180 251.233 -0.237
201903 -0.130 254.202 -0.169
201906 -0.010 256.143 -0.013
201909 -0.020 256.759 -0.026
201912 -0.020 256.974 -0.026
202003 -0.050 258.115 -0.064
202006 -0.030 257.797 -0.038
202009 -0.010 260.280 -0.013
202012 -0.160 260.474 -0.203
202103 0.070 264.877 0.087
202106 0.020 271.696 0.024
202109 0.060 274.310 0.072
202112 0.003 278.802 0.004
202203 0.004 287.504 0.005
202206 -0.030 296.311 -0.033
202209 -0.010 296.808 -0.011
202212 -0.060 296.797 -0.067
202303 -0.060 301.836 -0.066
202306 -0.030 305.109 -0.032
202309 -0.020 307.789 -0.021
202312 -0.070 306.746 -0.075
202403 -0.040 312.332 -0.042
202406 -0.060 314.175 -0.063
202409 -0.040 315.301 -0.042
202412 -0.050 315.605 -0.052
202503 -0.030 319.799 -0.031
202506 -0.060 322.561 -0.061
202509 -0.070 324.800 -0.071
202512 -0.140 324.054 -0.143
202603 -0.070 330.213 -0.070

Add all the adjusted EPS together and divide 10 will get our e10.

Frequently Asked Questions Learn more about E10 →
What does a E10 of $-0.16 mean?
Tecogen (TGEN) has a E10 of $-0.16 as of Mar. 2026. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on Tecogen and its competitors.
Is Tecogen's E10 too high?
Tecogen's current E10 is $-0.16. Overall, Tecogen has a GF Score™ of 50/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Tecogen's E10 compare to RFIL and ESP?
Tecogen's E10 of $-0.16 can be compared against companies in the Industrial Products industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good E10 for an Industrial Products company?
A good E10 depends on the Industrial Products industry context. However, E10 should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high E10 mean?
A high E10 can signal that a stock is expensive relative to its fundamentals. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on Tecogen and its competitors. Tecogen's current E10 is $-0.16. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Tecogen stock overvalued right now?
Based on GuruFocus' analysis, Tecogen (TGEN) is currently considered Significantly Overvalued. The stock's GF Value™ is $1.18, compared to a current price of $5.38 — trading 355.9% above its estimated fair value. The current E10 is $-0.16. Tecogen's overall GF Score™ is 50/100 with 3 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is E10 calculated?
E10 is calculated from a company's financial statements. For Tecogen (TGEN), the current E10 is $-0.16 as of Mar. 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is Tecogen (TGEN) Overvalued in 2026?

Based on GuruFocus' analysis, Tecogen stock appears to be overvalued. The current stock price of $5.38 is trading 355.9% above its estimated GF Value™ of $1.18. GuruFocus considers Tecogen to be Significantly Overvalued.

Key valuation signals for TGEN:

  • E10: $-0.16
  • GF Value™: $1.18 vs. price of $5.38 (355.9% above fair value)
  • GF Score™: 50/100 with 3 warning signs

No single metric tells the full story. See the TGEN stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Tecogen Business Description

Other Exchanges 2T1:Germany
Address 76 Treble Cove Road, Building 1, North Billerica, MA, USA, 01862
Tecogen Inc produces commercial and industrial, natural-gas-fueled engine-driven, combined heat and power (CHP) products that reduce energy costs, decrease greenhouse gas emissions and alleviate congestion on the national power grid. Its products supply electric power or mechanical power for cooling. The company has three business segments: Products Segment, Services Segment, and Energy Production Segment. The majority of the company's revenue is derived from the Services segment, which provides operations and maintenance (O&M) services for its products under long term service contracts.
50GF Score

Get the complete analysis for TGEN

E10 is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

$5.38
Price
$1.18
GF Value