Gem DiamondsGMDMF ROC (Joel Greenblatt) % is -47.75% as of Dec. 2025. The stock has 5 warning signs investors should review. Among 2,502 Metals & Mining companies, Gem Diamonds ranks worse than 54.56% on this metric.
Joel Greenblatt defined Return on Capital differently in his book The Little Book That Still Beats the Market (Little Books. Big Profits). He defines ROC (Joel Greenblatt) % as EBIT divided by the total of Property, Plant and Equipment and net working capital. Gem Diamonds's annualized ROC (Joel Greenblatt) % for the quarter that ended in Dec. 2025 was -47.75%.
The historical rank and industry rank for Gem Diamonds's ROC (Joel Greenblatt) % or its related term are showing as below:
GMDMF'
s ROC (Joel Greenblatt) % Range Over the Past 10 Years
Min: -44.24 Med: 10.14 Max: 27.29
Current: -29.19
During the past 13 years, Gem Diamonds's highest ROC (Joel Greenblatt) % was 27.29%. The lowest was -44.24%. And the median was 10.14%.
GMDMF's ROC (Joel Greenblatt) % is ranked worse than 54.56% of 2502
companies
in the Metals & Mining industry
Industry Median: -22.105
vs GMDMF: -29.19
Gem Diamonds's 5-Year average Growth Rate of ROC (Joel Greenblatt) % was 0.00% per year.
The way Joel Greenblatt defines Return on Capital is a more accurate measure of how efficiently the company generates returns onthe capital actually invested in the business. EBIT is used instead of net income because the tax and interest payment may be affected by factors other than the core business operation. Intangible assets are not included in the calculation because they don't need to be replaced.
Gem Diamonds ROC (Joel Greenblatt) % Related Terms
Gem Diamonds ROC (Joel Greenblatt) % Historical Data
* Premium members only.
The historical data trend for Gem Diamonds's ROC (Joel Greenblatt) % 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.
For the Other Precious Metals & Mining subindustry, Gem Diamonds's ROC (Joel Greenblatt) %, along with its competitors' market caps and ROC (Joel Greenblatt) % 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.
Gem Diamonds ROC (Joel Greenblatt) % vs Metals & Mining Industry
For the Metals & Mining industry and Basic Materials sector, Gem Diamonds's ROC (Joel Greenblatt) % distribution charts can be found below:
* The bar in red indicates where Gem Diamonds's ROC (Joel Greenblatt) % falls into.
Joel Greenblatt defined Return on Capital differently in his book The Little Book That Still Beats the Market (Little Books. Big Profits) . He defines Return on Capital as follows:
EBIT stands for Earnings Before Interest and Taxes.
Fixed Assets are also known as non-current assets. They include the Property, Plant and Equipment that the firm needs in its operation.
GuruFocus calculates net working capital as: (Accounts Receivable + Total Inventories + Other Current Assets) - (Accounts Payable & Accrued Expense + Deferred Revenue + Other Current Liabilities). We're trying to account for OPERATING assets and liabilities (part of daily business) when calculating working capital. Cash and marketable securities are considered NON-OPERATING assets and are not included in calculation. We will also back out all interest bearing debt, short term debt and the portion of long term debt that is due in the current period from the current liabilities. This debt will be considered when computing cost of capital and it would be inappropriate to count it twice.
Note:
The EBIT data used here is two times the semi-annual (Dec. 2025) EBIT 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.
What does a ROC (Joel Greenblatt) % of -47.75% mean?
Gem Diamonds (GMDMF) has a ROC (Joel Greenblatt) % of -47.75% as of Dec. 2025. Joel Greenblatt's return on capital is the ratio of EBIT to average fixed assets and net working capital. View historical data on Gem Diamonds and its competitors. According to the industry distribution chart, Gem Diamonds ranks #1365 out of 2502 companies in the Metals & Mining industry, placing it in the top 54.6%.
Is Gem Diamonds' ROC (Joel Greenblatt) % too high?
Gem Diamonds' current ROC (Joel Greenblatt) % is -47.75%. Based on the distribution chart, Gem Diamonds ranks #1365 out of 2502 companies in the Metals & Mining industry, which is below the industry midpoint.
How does Gem Diamonds' ROC (Joel Greenblatt) % compare to HL?
According to the Metals & Mining industry distribution chart, Gem Diamonds ranks #1365 out of 2502 companies for ROC (Joel Greenblatt) %. This places Gem Diamonds in the lower half of its industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good ROC (Joel Greenblatt) % for a Metals & Mining company?
A good ROC (Joel Greenblatt) % depends on the Metals & Mining industry context. However, ROC (Joel Greenblatt) % 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 ROC (Joel Greenblatt) % mean?
A high ROC (Joel Greenblatt) % can signal that a stock is expensive relative to its fundamentals. Joel Greenblatt's return on capital is the ratio of EBIT to average fixed assets and net working capital. View historical data on Gem Diamonds and its competitors. Gem Diamonds's current ROC (Joel Greenblatt) % is -47.75%. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Gem Diamonds stock overvalued right now?
Based on GuruFocus' analysis, Gem Diamonds (GMDMF) is currently considered Significantly Overvalued. The stock's GF Value™ is $0.03, compared to a current price of $0.05 — trading 66.7% above its estimated fair value. The current ROC (Joel Greenblatt) % is -47.75%. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is ROC (Joel Greenblatt) % calculated?
ROC (Joel Greenblatt) % is calculated from a company's financial statements. For Gem Diamonds (GMDMF), the current ROC (Joel Greenblatt) % is -47.75% 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.
Gem Diamonds Ltd is a United Kingdom-based company engaged in the exploration and development of diamond mines. The company's geographical segments include Lesotho (diamond mining activities); Belgium (sales, marketing, and manufacturing of diamonds); and BVI, RSA, the UK, and Cyprus (technical and administrative services) and Botswana (diamond mining activities, currently on care and maintenance). It generates maximum revenue from the Belgium region. Its projects include Letseng Diamond mine and Ghaghoo Diamond mine. The company's revenue is derived from mining activities, polished manufacturing margins, and diamond analysis and manufacturing services.
Quick Browse
Personalize
Premium Gurus 
Create New Portfolio
GMDMF has been successfully added to your 