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I Built a System That Grades Every Stock the Way Buffett Reads Financial Statements

Then I crossed it with Peter Lynch's stock classification system. The results changed how I invest.

Author: John Gillespie
Organization: InsightfulAgents.AI LLC
Published:

Educational publication. Not investment advice. Neither John Gillespie nor InsightfulAgents.AI LLC is a registered investment adviser.

Warren Buffett doesn't use a stock screener. He reads financial statements. Income statement, balance sheet, cash flow, in that order. He's looking for specific numbers that tell him whether a business has a durable competitive advantage.

Peter Lynch doesn't treat every stock the same. A fast-growing tech company and a slow-growing utility require completely different analysis. Judging them by the same criteria is how retail investors end up confused.

Most retail investors do neither. They check a price target, read an analyst rating, and hope for the best.

I spent the last three months building OCCAM'S FORENSIC JURY, a system that combines both approaches and tracks every call it makes against real market data.

The Problem with One-Size-Fits-All Analysis

Here's what most stock tools give you: a DCF model, an intrinsic value, and a verdict. Buy, sell, or hold.

But that single model carries all the assumptions of whoever built it. And it treats every stock the same way. A high-growth SaaS company gets the same analysis framework as a REIT paying 8% dividends.

That's like grading a sprinter and a marathon runner on the same scorecard. Technically possible. Practically useless.

What Buffett Actually Looks For

When Buffett reads a 10-K, he's running a mental checklist. Not complicated. Not secret. But remarkably few investors actually do it:

Seven metrics. Pass or fail. No ambiguity.

What Lynch Actually Does

Lynch classifies every stock into one of six categories before analyzing it. Each category has different expectations, different risk, and different kill criteria:

The Matrix: Where Buffett Meets Lynch

The Forensic Jury does three things automatically for every stock:

  1. Classifies it into a Lynch category based on growth rate, sector, and financial profile.
  2. Runs all seven Buffett metrics and scores it (e.g., 6 of 7 pass).
  3. Generates a kill signal if the stock fails the critical metric for its category.

Then it asks one question: "What does a Buffett-style screen produce on this name?"

For a Fast Grower passing all seven metrics, the Forensic Jury produces a "compounding-machine, wide-moat" classification consistent with Buffett's stated framework.

For a Slow Grower failing the debt test, the methodology produces an "income-sustainability-at-risk" flag. The dividend coverage math signals strain.

For a Turnaround with more debt than cash, the methodology produces an "avoid-entirely" flag. There's no financing path that makes the math work.

No ambiguity. No "it depends." A clear, defensible methodology grounded in the same principles behind one of the most studied investment approaches in history.

Tracking Every Verdict

I'm not asking anyone to trust a black box. Every methodology verdict the Forensic Jury produces is tracked against subsequent market behavior, updated daily, fully transparent.

Did entries flagged by the Forensic Jury as quality-screen-passing trade up? Did flagged entries trade down?

You can see the historical accuracy tracker right on the dashboard. Early results are encouraging, but the real value comes from the growing dataset. Every week adds more data points. Every data point makes the Forensic Jury more accountable.

This isn't a backtest run on historical data to find patterns that already happened. This is live methodology output measured against subsequent market behavior. Not a recommendation to act, just an accountability log of methodology performance.

The Part Most People Skip

Here's what I've learned building this: the kill signal is more valuable than the buy signal.

Most investors spend their energy finding stocks to buy. The real edge is knowing which stocks to avoid, and having a systematic reason why.

When the Forensic Jury flags a kill signal on a stock you're watching, it sends you an email. Not "this stock dropped 5%." Not "an analyst downgraded it." But: "This stock failed a critical Buffett financial metric for its Lynch category. The original thesis may no longer hold."

That's the kind of educational signal that helps you do your own research before things get worse. And it's the one most platforms don't give you.

Try It

Every valuation on Occam's Investing now includes:

Run any stock through the Forensic Jury for free. No account required:

insightfulagents.ai/free-valuation.html

Premium members get watchlist tracking, kill-signal email alerts, and portfolio scoring by Lynch category. Premium is $20/month; Premium+ is $75/month:

insightfulagents.ai/occams-investing.html


Follow the Cash. Not the Narrative. Because Profit is Opinion and Cash is Fact.

Frequently asked

What is the Buffett-Lynch combination?

Warren Buffett evaluated companies on seven financial-statement metrics like gross margin and debt-to-equity. Peter Lynch sorted companies into six categories with different kill criteria. Combining them means classifying a stock first, then asking whether it passes the financial-statement bar for its category.

What is a kill signal?

A category-specific financial-statement red flag indicating the original thesis may no longer hold. For Slow Growers (income stocks), if debt-to-equity exceeds 0.80 or net margin falls below 20%, the dividend is at risk.

Does the methodology produce buy/sell recommendations?

No. OCCAM'S FORENSIC JURY produces classification and pass/fail scoring outputs. Whether a given output translates into a personal investment decision is up to the reader and their own due diligence. The author and InsightfulAgents.AI LLC are not registered investment advisers.

Related

§ 4. Disclosure and disclaimer

This article is published as educational and methodological commentary. It is not personalized investment advice and does not constitute a recommendation to buy, sell, or hold any security. The author and InsightfulAgents.AI LLC are not registered investment advisers, broker-dealers, or financial planners under the Investment Advisers Act of 1940 or any state-level analogue, and nothing in this article should be construed as creating a fiduciary relationship.

The author may or may not hold positions in any security or entity discussed; positions can change without notice. All claims are sourced to SEC filings, earnings transcripts, or named third-party data. Past performance does not guarantee future results.

For a full disclosure framework, see /legal.html.