PnL tells you what happened to money. A journal tells you what happened to process. Without written trade context, you cannot tell whether a good result came from a good decision or from a lucky price move that should not be repeated.

• It separates good process from lucky outcomes.
• It preserves the pre-trade thesis before hindsight rewrites it.
• It makes review possible across dozens of trades, not just memorable ones.
• It exposes repeated execution and sizing mistakes.

Start with the minimum fields required to understand the trade later: market, side, size, price, thesis, and the condition that would invalidate the setup. Then add optional modules only if they support a real review workflow you will follow consistently.

1. Choose the strategy type that best matches the trade.
2. Pick a workflow depth you can sustain after winning and losing streaks.
3. Turn on only the optional sections that improve actual review quality.
4. Copy the markdown template and structured CSV header into your system.

An arbitrage workflow may need both venues, leg prices, target net edge, execution quality, and a post-trade review of whether the opportunity was truly complementary. A simple directional trade may need far fewer fields, but still benefits from explicit probability, invalidation, and lesson tracking.

• Arbitrage logs usually need more execution detail.
• Directional trades benefit from clean thesis and invalidation notes.
• Review prompts matter because they force interpretation, not just data capture.

The worst mistake is keeping only outcome data. If your journal says who won, how much you made, and nothing about the thesis or fill quality, it cannot teach you much. The second mistake is making the template so demanding that you stop filling it out during active periods.

• Tracking only PnL and not the decision process
• Using one rigid template for every strategy type
• Building a journal too heavy to keep current
• Skipping notes on the trades that went wrong

Good journal standard: If the template feels too heavy to fill out after a stressful loss, simplify it now. A lighter journal used consistently is far more valuable than a perfect journal abandoned after a week.