Formosa Optical Technology CoROCO:5312 -0.66%81 Operating Margin % is 7.70% as of Dec. 2025, which is 40% above its 10-year median of 5.50. GuruFocus rates ROCO:5312 with a GF Score™ of 81/100 and a GF Value™ of NT$108.45 (Modestly Undervalued). The stock has 3 warning signs investors should review. Among 816 Medical Devices & Instruments companies, Formosa Optical Technology Co ranks better than 58.95% on this metric.
Formosa Optical Technology Co Ltd operating margin is expanding. Margin expansion is usually a good sign.
The historical rank and industry rank for Formosa Optical Technology Co's Operating Margin % or its related term are showing as below:
ROCO:5312'
s Operating Margin % Range Over the Past 10 Years
Min: 2.34 Med: 5.5 Max: 8.49
Current: 7.24
ROCO:5312's Operating Margin % is ranked better than 58.95% of 816
companies
in the Medical Devices & Instruments industry
Industry Median: 3.465
vs ROCO:5312: 7.24
Formosa Optical Technology Co (ROCO:5312) Operating Margin % Explanation
Just like Gross Margin %, it is important to see a company maintains its operating margin over time. Among the same industry, a company with higher operating margin is more efficient in its operation. It is also more stable during industry slowdown or recessions. Peter Lynch prefers those with higher margins than those with lower margins.
Be Aware
Operating Margin % can be manipulated by adjusting the rate of depreciation, depletion and amortization (DDA).
If a company is facing competition, its Operating Margin % may decline. Often the Operating Margin % declines well before the company's Revenue or even profit decline. Therefore, Operating Margin % is a very important indicator of whether the company is facing problems.
For instance, by 2012, Nokia (NOK)'s problems were well known and its stock had lost more than 90% of its market value since 2007. But Nokias Operating Margin % had already been in decline since 2002, although its Earnings per Share (Diluted) were still rising. Investors who paid attention to Operating Margin % would have avoided this huge loss. The same can be said for Research-in-Motion (RIMM).
Therefore, Operating Margin % is a very important screening filter for GuruFocus. GuruFocus's Buffett-Munger screener requires that the profit margin is either consistent or expanding. The Model Portfolio of the Buffett-Munger screener has outperformed the market every year since inception in 2009.
Formosa Optical Technology Co Operating Margin % Related Terms
Formosa Optical Technology Co Operating Margin % Historical Data
* 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 Operating Margin % Chart
ROCO:5312 vs ISRG, BDX, MDLN: Operating Margin % Comparison
For the Medical Instruments & Supplies subindustry, Formosa Optical Technology Co's Operating Margin %, along with its competitors' market caps and Operating Margin % 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 Operating Margin % vs Medical Devices & Instruments Industry
For the Medical Devices & Instruments industry and Healthcare sector, Formosa Optical Technology Co's Operating Margin % distribution charts can be found below:
* The bar in red indicates where Formosa Optical Technology Co's Operating Margin % falls into.
Formosa Optical Technology Co Operating Margin % Calculation
Operating Margin % - also known as operating income margin, operating profit margin and return on sales (ROS) - is the ratio of Operating Income divided by net sales or Revenue, usually presented in percent.
* 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 (ROCO:5312) has a Operating Margin % of 7.70% as of Dec. 2025. Operating margin is the ratio of total operating income to net sales. View historical data on Formosa Optical Technology Co and its competitors. This is 40% above median its historical median of 5.50. Over the past decade, Formosa Optical Technology Co's Operating Margin % has ranged from 2.34 to 8.49. According to the industry distribution chart, Formosa Optical Technology Co ranks #335 out of 816 companies in the Medical Devices & Instruments industry, placing it in the top 41.1%.
Is Formosa Optical Technology Co's Operating Margin % too high?
Formosa Optical Technology Co's current Operating Margin % of 7.70% is 40% above median its 10-year median of 5.50. Over the past 10 years, this metric has ranged from a low of 2.34 to a high of 8.49. The Medical Devices & Instruments industry median Operating Margin % is 3.47. Formosa Optical Technology Co's value of 7.70% is 122.2% above this industry median. Based on the distribution chart, Formosa Optical Technology Co ranks #335 out of 816 companies in the Medical Devices & Instruments industry, which is above the industry midpoint. Overall, Formosa Optical Technology Co has a GF Score™ of 81/100 and is considered Modestly Undervalued, reflecting its overall financial health beyond just this single metric.
How does Formosa Optical Technology Co's Operating Margin % compare to ISRG and BDX?
According to the Medical Devices & Instruments industry distribution chart, Formosa Optical Technology Co ranks #335 out of 816 companies for Operating Margin %. This puts Formosa Optical Technology Co in the upper half of its industry. The industry median Operating Margin % is 3.47. Formosa Optical Technology Co's value of 7.70% is 122.2% above this benchmark. Historically, Formosa Optical Technology Co's own Operating Margin % has ranged from 2.34 to 8.49 over the past decade. While the company's 10-year median is 5.50 vs. the industry median of 3.47, Formosa Optical Technology Co has consistently been above the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Operating Margin % for a Medical Devices & Instruments company?
The median Operating Margin % among Medical Devices & Instruments companies is 3.47, based on 816 companies in the industry. Companies in the top quartile (top 25%) have a Operating Margin % significantly above this median, while those in the bottom quartile fall well below. However, Operating Margin % should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Formosa Optical Technology Co's current Operating Margin % of 7.70% is 122.2% above the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Operating Margin % mean?
A high Operating Margin % can signal that a stock is expensive relative to its fundamentals. Operating margin is the ratio of total operating income to net sales. View historical data on Formosa Optical Technology Co and its competitors. For the Medical Devices & Instruments industry, the median Operating Margin % is 3.47 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Formosa Optical Technology Co's current Operating Margin % is 7.70%, which is 40% above median its own 10-year median of 5.50. 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$108.45, compared to a current price of NT$89.70 — trading 17.3% below its estimated fair value. The current Operating Margin % is 7.70%, which is 40% above median its 10-year median of 5.50 and 122.2% above the Medical Devices & Instruments industry median of 3.47. Formosa Optical Technology Co's overall GF Score™ is 81/100 with 3 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Operating Margin % calculated?
Operating Margin % is calculated from a company's financial statements. For Formosa Optical Technology Co (ROCO:5312), the current Operating Margin % is 7.70% 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$89.70 is trading 17.3% below its estimated GF Value™ of NT$108.45.
GuruFocus considers Formosa Optical Technology Co to be Modestly Undervalued.
Key valuation signals for ROCO:5312:
Operating Margin %: 7.70% (40% above median its 10-year median of 5.50)
GF Value™: NT$108.45 vs. price of NT$89.70 (17.3% below fair value)
Industry Position: 122.2% above the Medical Devices & Instruments median (#335 of 816)
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
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.
81GF Score
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