Rule One intrinsic value, right on Yahoo Finance
Rule One Valuation applies the Rule One formula to any quote page — sticker price, margin-of-safety buy price, and a BUY / WATCH / AVOID signal in one click. No spreadsheet required.
Coming to the Chrome Web Store soon
| Intrinsic Value | $410.23 |
|---|---|
| MOS Buy Price | $205.11 |
| Current Price | $175.00 |
| Future Price (10yr) | $1,659.61 |
| CAGR | 25.2% |
What it does
Instant valuation
Open the popup on any Yahoo Finance quote page and see intrinsic value immediately — no copy-paste, no spreadsheet.
BUY / WATCH / AVOID
One clear signal tells you where the current price sits relative to intrinsic value and your margin of safety.
Override assumptions
Growth rate and PE are pulled in automatically. Edit either field to stress-test different scenarios on the fly.
See the math
Every formula step is shown in full — PE cap, future EPS, discounting back at your MARR, and the MOS buy price.
Configurable defaults
MARR, projection years, and margin of safety are all adjustable in Settings. Your choices sync across Chrome profiles.
No data collected
Uses only public market data. Nothing stored on any server. No analytics, no tracking.
The Math
The Rule One formula, step by step
Growth rate and PE are pulled in automatically from public market data. Override either field to test your own assumptions. Hit "See the math" for a full breakdown of every step.
Defaults: MARR = 15%, projection = 10 years, MOS = 50%. All configurable in Settings.
The signal
Current price is at or below the margin-of-safety buy price — a 50% discount to intrinsic value.
Trading between MOS buy price and sticker price — fairly valued. Watch for a better entry.
Current price exceeds intrinsic value — overvalued at current growth assumptions.
Privacy
No data leaves your browser
The extension pulls in public market data on your behalf — nothing is routed through our servers. Your three settings are stored locally via Chrome sync. No analytics, no tracking.
Read the full privacy policy →