Edge & Error

Guides & tools for traders and investors

Find the edge.
Log the error.

Short, practical guides with tools that actually compute. Built from real trading experience and decision research, checked line by line, and updated every year.

Illustration of a return distribution: a fat left tail of losses in red, a small right-hand edge in green Error · the fat tail Edge · what you keep Losses Gains
Illustration, not data. Most results live in the middle. The money is lost in the red tail and earned in the thin green edge, so most of the work is cutting the red.

The shelf

Few products, each one finished properly.

  1. No. 01 · EN

    The Error Log

    Most journals record trades. This one finds the leak. Tag the one mistake behind each trade and the Error Log puts a price on it: which error cost you the most, in money and in R, and what your results look like without it. Your mental state is tracked too, so you see which moods make you money and which cost you.

    Offline app for PC and phone · 25-page field manual on the psychology behind trading errors · Excel and Google Sheets version · no account, no subscription, your data stays on your device

    Get the Error Log → · Try the live demo →

    LaunchingWinter 2026
  2. No. 02 · EN

    Position Sizing & Risk Toolkit

    How much to risk, where the stop goes and how losing streaks really behave, with calculators instead of rules of thumb.

    Manual + sizing calculator + drawdown simulator

    Planned2027
  3. No. 01 · RO

    Declarația Unică pentru investitori

    For investors in Romania: how to declare gains and dividends from XTB, Trading 212, Revolut and others, with worked examples and a calculator. Romanian edition →

    PlannedFebruary 2027

How we make things

The opposite of a 200-page PDF nobody finishes.

01

Sourced, not generated

Every claim traces back to data, research or a rule you can check. Sources are listed at the end of each guide.

02

Tools that compute

Each guide ships with a spreadsheet or template that does the maths for you, with your own numbers.

03

Short on purpose

Worked examples instead of filler. If a chapter does not change what you do, it is cut.

04

Kept current

Each guide carries a version and a changelog. Buyers get every update to their edition free.

Free starter kit

Find your costliest mistake in five minutes.

Four Error Cards, the pre-trade checklist and a five-minute exercise on your last ten trades. Free, as a PDF. Then an occasional email with one useful idea. Nothing else.

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