Formosa Optical Technology Co (ROCO:5312) E10: NT$6.56 (As of Dec. 2025)


ROCO:5312 Formosa Optical Technology Co Ltd ROCO:5312
82 GF Score
Price NT$88.60
GF Value NT$108.60
Valuation Modestly Undervalued
! 4 Warning Signs
View Full Analysis

What is Formosa Optical Technology Co E10?

Formosa Optical Technology Co ROCO:5312 +0.57% 82 E10 is NT$6.56 as of Dec. 2025. GuruFocus rates ROCO:5312 with a GF Score™ of 82/100 and a GF Value™ of NT$108.60 (Modestly Undervalued). The stock has 4 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.

Formosa Optical Technology Co's adjusted earnings per share data for the three months ended in Dec. 2025 was NT$1.050. Add all the adjusted EPS for the past 10 years together and divide 10 will get our e10, which is NT$6.56 for the trailing ten years ended in Dec. 2025.

During the past 12 months, Formosa Optical Technology Co's average E10 Growth Rate was -0.50% per year. During the past 3 years, the average E10 Growth Rate was 1.70% per year. During the past 5 years, the average E10 Growth Rate was 2.30% per year. 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 Formosa Optical Technology Co was 3.20% per year. The lowest was 1.70% per year. And the median was 2.45% per year.

As of today (2026-07-03), Formosa Optical Technology Co's current stock price is NT$88.60. Formosa Optical Technology Co's E10 for the quarter that ended in Dec. 2025 was NT$6.56. Formosa Optical Technology Co's Shiller PE Ratio of today is 13.51.

During the past 13 years, the highest Shiller PE Ratio of Formosa Optical Technology Co was 25.15. The lowest was 8.82. And the median was 11.76.


Formosa Optical Technology Co  (ROCO:5312) 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.

Formosa Optical Technology Co's Shiller P/E Ratio of today is calculated as

Shiller PE Ratio=Share Price/E10
=88.60/6.56
=13.51

* 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.

During the past 13 years, the highest Shiller P/E Ratio of Formosa Optical Technology Co was 25.15. The lowest was 8.82. And the median was 11.76.


Be Aware

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


Formosa Optical Technology Co E10 Related Terms


Formosa Optical Technology Co E10 Historical Data

* Premium members only.

The historical data trend for Formosa Optical Technology Co'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.

Formosa Optical Technology Co E10 Chart

Formosa Optical Technology Co 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 6.25 6.24 6.36 6.59 6.56

Formosa Optical Technology Co Quarterly Data
Mar21 Jun21 Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25
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 6.59 6.66 6.59 6.64 6.56

ROCO:5312 vs ISRG, BDX, MDLN: E10 Comparison

For the Medical Instruments & Supplies subindustry, Formosa Optical Technology Co'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.


Formosa Optical Technology Co Shiller PE Ratio vs Medical Devices & Instruments Industry

For the Medical Devices & Instruments industry and Healthcare sector, Formosa Optical Technology Co's Shiller PE Ratio distribution charts can be found below:

* The bar in red indicates where Formosa Optical Technology Co's Shiller PE Ratio falls into.


ROCO:5312
82GF Score
Formosa Optical Technology Co Ltd ROCO:5312
E10 is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

Formosa Optical Technology Co 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, Formosa Optical Technology Co's adjusted earnings per share data for the three months ended in Dec. 2025 was:

Adj_EPS= Earnings per Share (Diluted) /CPI of Dec. 2025 (Change)*Current CPI (Dec. 2025)
=1.05/324.0540*324.0540
=1.050

Current CPI (Dec. 2025) = 324.0540.

Formosa Optical Technology Co Quarterly Data

per share eps CPI Adj_EPS
201603 1.660 238.132 2.259
201606 1.420 241.018 1.909
201609 1.980 241.428 2.658
201612 0.910 241.432 1.221
201703 1.710 243.801 2.273
201706 0.780 244.955 1.032
201709 1.620 246.819 2.127
201712 0.940 246.524 1.236
201803 0.550 249.554 0.714
201806 1.160 251.989 1.492
201809 1.210 252.439 1.553
201812 1.290 251.233 1.664
201903 1.230 254.202 1.568
201906 1.300 256.143 1.645
201909 1.590 256.759 2.007
201912 2.170 256.974 2.736
202003 0.920 258.115 1.155
202006 0.630 257.797 0.792
202009 1.750 260.280 2.179
202012 1.820 260.474 2.264
202103 1.270 264.877 1.554
202106 0.330 271.696 0.394
202109 1.230 274.310 1.453
202112 1.980 278.802 2.301
202203 1.060 287.504 1.195
202206 -0.310 296.311 -0.339
202209 1.560 296.808 1.703
202212 0.520 296.797 0.568
202303 1.960 301.836 2.104
202306 1.370 305.109 1.455
202309 1.970 307.789 2.074
202312 1.640 306.746 1.733
202403 2.360 312.332 2.449
202406 1.790 314.175 1.846
202409 2.490 315.301 2.559
202412 1.580 315.605 1.622
202503 2.000 319.799 2.027
202506 0.760 322.561 0.764
202509 2.590 324.800 2.584
202512 1.050 324.054 1.050

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 NT$6.56 mean?
Formosa Optical Technology Co (ROCO:5312) has a E10 of NT$6.56 as of Dec. 2025. E10 represents the company's inflation-adjusted earnings per share over a 10-year period. View historical data on Formosa Optical Technology Co and its competitors.
Is Formosa Optical Technology Co's E10 too high?
Formosa Optical Technology Co's current E10 is NT$6.56. Overall, Formosa Optical Technology Co has a GF Score™ of 82/100 and is considered Modestly Undervalued, reflecting its overall financial health beyond just this single metric.
How does Formosa Optical Technology Co's E10 compare to ISRG and BDX?
Formosa Optical Technology Co's E10 of NT$6.56 can be compared against companies in the Medical Devices & Instruments 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 a Medical Devices & Instruments company?
A good E10 depends on the Medical Devices & Instruments 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 Formosa Optical Technology Co and its competitors. Formosa Optical Technology Co's current E10 is NT$6.56. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Formosa Optical Technology Co stock overvalued right now?
Based on GuruFocus' analysis, Formosa Optical Technology Co (ROCO:5312) is currently considered Modestly Undervalued. The stock's GF Value™ is NT$108.60, compared to a current price of NT$88.60 — trading 18.4% below its estimated fair value. The current E10 is NT$6.56. Formosa Optical Technology Co's overall GF Score™ is 82/100 with 4 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 Formosa Optical Technology Co (ROCO:5312), the current E10 is NT$6.56 as of Dec. 2025. 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 Formosa Optical Technology Co (ROCO:5312) Overvalued in 2026?

Based on GuruFocus' analysis, Formosa Optical Technology Co stock appears to be undervalued. The current stock price of NT$88.60 is trading 18.4% below its estimated GF Value™ of NT$108.60. GuruFocus considers Formosa Optical Technology Co to be Modestly Undervalued.

Key valuation signals for ROCO:5312:

  • E10: NT$6.56
  • GF Value™: NT$108.60 vs. price of NT$88.60 (18.4% below fair value)
  • GF Score™: 82/100 with 4 warning signs

No single metric tells the full story. See the ROCO:5312 stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Formosa Optical Technology Co Business Description

Address No. 97, Xintai 5th Road, 16th Floor, Section 1, Xizhi District, New Taipei City, TWN
Formosa Optical Technology Co Ltd is mainly engaged in the eyewear business, including optometry services and the retail business selling contact lenses and eye drops. The Group mainly derives revenue from the business divisions of Formosa Optical Technology and Bo Wei Optical, with Formosa Optical Technology generating maximum revenue. The majority of revenue is derived from the sale of glasses. The Group generates the majority of its revenue from Taiwan.
82GF Score

Get the complete analysis for ROCO:5312

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

NT$88.60
Price
NT$108.60
GF Value