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Richard Sloan from the University of Michigan was first to document what is referred to as the "accrual anomaly". His 1996 paper found that shares of companies with small or negative accruals vastly outperform (+10%) those of companies with large ones.
Proto Labs's Sloan Ratio for the quarter that ended in Mar. 2026 was -4.15%.
As of Mar. 2026, Proto Labs has a Sloan Ratio of -4.15%, indicating the company is in the safe zone and there is no funny business with accruals.
Proto Labs (WBO:PRLB) Sloan Ratio % Explanation
A former University of Michigan researcher, Richard Sloan's 1996 paper found that shares of companies with small or negative accruals vastly outperform (+10%) those of companies with large ones. In fact, for the 40-year period between 1962 and 2001, buying the lowest accrual companies and shorting the highest accrual companies resulted in an average annual compounded return of 18%, more than double the S&P 500's 7.4% annual return over the same period.
If the Sloan Ratio is between -10% and 10%, the company is in the safe zone and there is no funny business with accruals.
If the Sloan Ratio is less than between -25% and -10% on the negative side, and between 10% and 25% on the positive side, this is a warning stage of accrual build up.
If the Sloan Ratio is less than -25% or greater than 25%, and this ratio is consistent over several quarters or even years, be careful. Earnings are highly likely to be made up of accruals.
As of Mar. 2026, Proto Labs has a Sloan Ratio of -4.15%, indicating the company is in the safe zone and there is no funny business with accruals.
Proto Labs Sloan Ratio % Related Terms
Proto Labs Sloan Ratio % Historical Data
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The historical data trend for Proto Labs's Sloan Ratio % 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.
WBO:PRLB vs RYZ, WOR, MEC: Sloan Ratio % Comparison
For the Metal Fabrication subindustry, Proto Labs's Sloan Ratio %, along with its competitors' market caps and Sloan 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.
Proto Labs Sloan Ratio % vs Industrial Products Industry
For the Industrial Products industry and Industrials sector, Proto Labs's Sloan Ratio % distribution charts can be found below:
* The bar in red indicates where Proto Labs's Sloan Ratio % falls into.
Earnings contain a lot of non cash earnings which is called accruals. The Sloan ratio is a way to identify firms with low non-cash or accrual-derived earnings relative to their cash flow.
Proto Labs's Sloan Ratio for the fiscal year that ended in Dec. 2025 is calculated as
Proto Labs's Net Income for the trailing twelve months (TTM) ended in Mar. 2026 was 3.838 (Jun. 2025 ) + 6.148 (Sep. 2025 ) + 5.123 (Dec. 2025 ) + 7.016 (Mar. 2026 ) = €22.1 Mil.
Proto Labs's Cash Flow from Operations for the trailing twelve months (TTM) ended in Mar. 2026 was 9.176 (Jun. 2025 ) + 24.785 (Sep. 2025 ) + 14.049 (Dec. 2025 ) + 15.169 (Mar. 2026 ) = €63.2 Mil.
Proto Labs's Cash Flow from Investing for the trailing twelve months (TTM) ended in Mar. 2026 was -0.557 (Jun. 2025 ) + -3.623 (Sep. 2025 ) + -4.788 (Dec. 2025 ) + -4.124 (Mar. 2026 ) = €-13.1 Mil.
* 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.
Proto Labs (WBO:PRLB) has a Sloan Ratio % of -4.15% as of Mar. 2026. Sloan ratio measures earnings quality based on the amount of accruals. View historical data on Proto Labs and its competitors.
Is Proto Labs' Sloan Ratio % too high?
Proto Labs' current Sloan Ratio % is -4.15%. Overall, Proto Labs has a GF Score™ of 60/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Proto Labs' Sloan Ratio % compare to RYZ and WOR?
Proto Labs' Sloan Ratio % of -4.15% 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 Sloan Ratio % for an Industrial Products company?
A good Sloan Ratio % depends on the Industrial Products industry context. However, Sloan Ratio % 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 Sloan Ratio % mean?
A high Sloan Ratio % can signal that a stock is expensive relative to its fundamentals. Sloan ratio measures earnings quality based on the amount of accruals. View historical data on Proto Labs and its competitors. Proto Labs's current Sloan Ratio % is -4.15%. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Proto Labs stock overvalued right now?
Based on GuruFocus' analysis, Proto Labs (WBO:PRLB) is currently considered Significantly Overvalued. The stock's GF Value™ is €37.83, compared to a current price of €69.60 — trading 84% above its estimated fair value. The current Sloan Ratio % is -4.15%. Proto Labs' overall GF Score™ is 60/100 with 7 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Sloan Ratio % calculated?
Sloan Ratio % is calculated from a company's financial statements. For Proto Labs (WBO:PRLB), the current Sloan Ratio % is -4.15% 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 Proto Labs (WBO:PRLB) Overvalued in 2026?
Based on GuruFocus' analysis, Proto Labs stock appears to be overvalued.
The current stock price of €69.60 is trading 84% above its estimated GF Value™ of €37.83.
GuruFocus considers Proto Labs to be Significantly Overvalued.
Key valuation signals for WBO:PRLB:
Sloan Ratio %: -4.15%
GF Value™: €37.83 vs. price of €69.60 (84% above fair value)
No single metric tells the full story. See the WBO:PRLB stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Proto Labs Inc is an on-demand manufacturer of custom parts for prototyping and short-run production. The company offers developers and engineers quick-turn production services to reduce the time to market. The Lab uses injection molding, computer numerical control machining, and 3-D printing, and sheet metal to manufacture custom parts for its clients. The company services clients' needs for prototype solutions, parts for testing procedures, bridge production capabilities during disruptions in manufacturing processes, limited-quantity requests, and end-of-life production support. Geographically, a majority of the company's revenue is derived from the United States and the rest from Europe.
60GF Score
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