A calm, evidence-based framework for long-term stock investing

Build a repeatable investing process for quality stocks.

Portfolio System Lab helps busy DIY investors research, value, and manage long-term stock portfolios with clear frameworks—so decisions feel calmer and more consistent.

What you’ll get

  • A Quality Scorecard to filter for durable businesses
  • A 1-page Thesis Template to make every decision traceable
  • Portfolio rules for sizing, trims, and review cadence

Educational content only. Not investment advice.

The Compounder Toolkit (free)

Download the templates to research a stock in under 60 minutes.

No spam. Unsubscribe anytime. Educational content only.
Quality scorecard preview 1-page thesis template preview Valuation range template preview Portfolio rules card preview

Inside the toolkit

  • Quality Compounder Scorecard (100 points)
  • 1-page Stock Thesis Template (with kill criteria)
  • Valuation Range Template (Low / Mid / High + margin of safety)
  • Portfolio Rules Card (position sizing + sell/trim rules)

How it works

1) Filter for quality

Use the scorecard to separate durable businesses from stories.

2) Write a thesis you can defend

Capture the moat, growth engine, risks, and kill criteria in one page.

3) Manage with rules

Position sizing, exposure caps, trim/sell rules, and a review cadence you can stick to.

Who it’s for (and who it’s not)

For you if you want

A calm, long-term approach and a repeatable process for researching quality stocks.

  • Clear checklists and templates
  • Valuation ranges + margin of safety
  • Portfolio rules that reduce decision stress

Not for you if you want

Constant action, hot takes, or “do this trade” style content.

  • Day trading or momentum chasing
  • Signals or copy-trading
  • Guaranteed returns or performance promises

Start here

Follow the framework in order: scorecard → thesis → valuation range → portfolio rules.

Read the full “Who it’s for / not for” page →

About

Portfolio System Lab exists to help investors replace guesswork with a repeatable framework—scorecards, theses, valuation ranges, and portfolio rules—so you can invest with clarity over years, not weeks.

Founder: [Cenk Yildiran] (replace this when ready)