Guy Spier
Value Investor's Checklist
Guy Spier's approach focuses on avoiding mistakes rather than finding clever opportunities. Inspired by Atul Gawande's Checklist Manifesto, Spier developed a structured checklist to counteract behavioral biases and emotional decision-making. His criteria emphasize asking the right questions before buying -- particularly identifying reasons NOT to invest -- creating a framework that is primarily qualitative and risk-focused.
Methodology fidelity
Thematic proxySources reviewed 2026-08-24Spier describes a living, qualitative error-prevention checklist used near the end of research, not an eight-factor stock score. The questions shown here are a compact adaptation of themes in his book rather than his complete current checklist. Only the valuation row is mechanically evaluated; its P/E and book-value gates and the owner-earnings DCF parameters are app choices. The seven qualitative rows are displayed but excluded from the score denominator.
Valuation Method
Conservative Owner Earnings
App modelOwner earnings DCF modeled after Buffett's approach but with extra conservatism -- a 12% discount rate (vs Buffett's 9%), growth capped at 10%, and 2.5% terminal growth. Reflects Spier's philosophy of only buying with a wide margin of safety.
Screening implementation (8 criteria)
| # | Criterion | Metric | Threshold | Data Source |
|---|---|---|---|---|
| 1 | Sufficient Discount to Intrinsic Value | Margin of Safety | Buying at meaningful discount | DCF, asset-based, or relative valuation |
| 2 | Business Understanding | Comprehension Level | Deep understanding of the business | Qualitative assessment |
| 3 | 5-Year Hold Comfort | Ownership Conviction | Comfortable owning if market closed for 5 years | Qualitative: business durability assessment |
| 4 | Management Integrity | Management Quality | Honest and competent management | Qualitative: track record, compensation, insider buying |
| 5 | Declining Industry (Avoid) | Industry Trajectory | NOT in a declining industry | Qualitative: industry analysis |
| 6 | Customer/Product Concentration (Avoid) | Revenue Concentration | NOT too dependent on one customer/product | 10-K: revenue breakdown, customer disclosures |
| 7 | Technology Disruption Risk (Avoid) | Disruption Vulnerability | Technology change unlikely to destroy business | Qualitative: competitive dynamics, industry trends |
| 8 | Insider Ownership | Insider Ownership | Meaningful insider ownership | Proxy filings: insider ownership percentage |
Intrinsic Value Method
Spier Owner Earnings DCF
App modelSum of [(OpCF + Interest - CapEx) * (1+g)^t / (1+r)^t] for t=1..10 + Terminal Value / (1+r)^10, where r = 12%, g capped at 10%Owner earnings DCF modeled after Buffett's approach but with extra conservatism -- a 12% discount rate, growth capped at 10%, and 2.5% terminal growth. Reflects Spier's philosophy of only buying with a wide margin of safety.
Verdict Logic
The mechanical result is driven by criterion 1 alone: qualitative criteria 2-8 are rendered for human review but excluded from pass/total arithmetic. The app’s value gate is a screening proxy, not Spier’s published verdict formula.
Sources
The Education of a Value Investor
primary2014Guy Spier
A memoir and practical guide describing Spier's evolution as a value investor, including the development of his investment checklist and rules for creating a rational decision-making environment.
View source →The Checklist Manifesto
secondary2009Atul Gawande
While not an investing book, Gawande's work on the power of checklists in surgery and aviation directly inspired Spier's approach to systematizing investment decisions and reducing errors.
View source →