The Author
SafetyMarginIO — Founder & Lead Analyst. SafetyMarginIO is the name behind this site — a long-term private investor who built SafetyMargin.io to apply Warren Buffett's value investing framework to every S&P 500 stock. The site exists to make rigorous intrinsic-value analysis free and accessible to investors who want to think like owners, not traders.
Contact: info@sabertec.net · X / Twitter
Why This Site Exists
Most retail investors do not have access to high-quality intrinsic-value analysis without paying for a Bloomberg terminal, a Morningstar Premium subscription, or a finance-industry data feed. SafetyMargin.io makes that analysis free for every S&P 500 stock — and does it using the specific frameworks Warren Buffett and Charlie Munger have advocated for decades: discounted cash flow, margin of safety, owner earnings, return on invested capital, economic moat, and honest forensic checks on the financial statements themselves.
The goal is not to tell you what to buy. The goal is to give you the same numbers an institutional analyst would look at, explain what they mean, and let you make your own decision.
Methodology
Every valuation on this site follows the same four-step process:
- Pull clean fundamentals. Annual revenue, free cash flow, owner earnings, invested capital, debt, equity, and share count come from Yahoo Finance's fundamentals-timeseries and quoteSummary endpoints.
- Compute the intrinsic value. A discounted cash flow model projects free cash flow (or owner earnings when available) forward using historically-grounded growth assumptions, discounts them back at a WACC between 8% and 12%, and adds a terminal value. Bear / Base / Bull scenarios are computed with the same engine.
- Verify the financial quality. The Beneish M-Score, Altman Z-Score, and Sloan Ratio act as a triple-gatekeeper on the financial statements. A stock can only be a bargain if the numbers are real.
- Compare to market sentiment. A composite sentiment score combines analyst ratings, price targets, EPS revisions, short interest, 52-week range, momentum, earnings surprises, and upgrade / downgrade flow — then cross-references sentiment with margin of safety to produce the Buffett Signal.
The full methodology for each component is documented in the Blog — start with Key Valuation Metrics, DCF Explained, and Forensic Accounting.
Data Sources
All data is sourced from Yahoo Finance public endpoints: quoteSummary v10, fundamentals-timeseries v1, and chart v8. Historical depth is typically 4 to 10 annual data points per field. The site does not use paid data feeds, and nothing is manually curated — which means the analysis is only as good as Yahoo's data coverage for a given ticker.
This Is Not Financial Advice
SafetyMargin.io is an educational tool. Every valuation is based on public data and transparent formulas; none of it is a recommendation to buy, sell, or hold any security. Do your own research, and see the full disclaimer for details.