What is a trading journal?
Last reviewed
A trading journal is a record of every trade you take - what you bought or sold, when, at what price and size - together with the reasoning behind it: why you entered, what you expected to happen, and what you learned when it was over. The numbers show what happened; the writing shows why. Reviewed regularly, the combination turns scattered trades into evidence about your own decision-making.
What belongs in a trading journal
A useful journal records two different kinds of information for each trade:
- The facts: instrument, direction, entry and exit prices, position size, fees, and the resulting profit or loss. These are objective and, ideally, imported rather than typed, so they cannot be misremembered.
- The reasoning: the thesis behind the entry, your confidence at the time, the market context, your emotional state, any mistakes you noticed, and the lesson you would carry forward. Only you can supply these, and they fade fast - a thesis reconstructed a week later is a story, not a record.
Many traders also tag trades by setup or strategy, attach a chart screenshot from the moment of entry, and grade their execution separately from the outcome - a distinction covered in how to review your trades.
Why keep one
Trading produces fast, noisy feedback: a bad decision can pay off and a good one can lose. Without a record, memory quietly edits the past - winners feel skillful, losers feel unlucky, and the same mistake repeats. A journal pins each decision to what you actually knew and felt at the time, so patterns become visible: the setup that never works, the position size that always precedes panic, the hour of day when discipline slips.
It also produces honest statistics. Win rate, average win against average loss, and expectancy can only be computed from a complete record - selective memory produces flattering, useless numbers. See the metrics that matter and how to calculate them.
Paper, spreadsheet, or automated
A notebook is better than nothing and costs nothing, but the facts are only as complete as your patience. A spreadsheet adds arithmetic - win rate and running P&L - at the price of manual entry for every fill, which is where most spreadsheet journals die.
An automated journal imports the facts from your exchange accounts or wallet addresses and leaves you only the part that cannot be automated: the writing. For active traders, and especially for crypto traders whose fills scatter across venues and chains, automation is usually the difference between a journal that survives and one that is abandoned in week three. The trade-offs are covered in choosing a trading journal.
The habit that makes it work
A journal only helps if it is written at the time and read afterwards. Write the thesis before or immediately after entering, complete the review when the position closes, and re-read a batch of entries on a regular schedule - weekly is common. The review loop, not the record itself, is what improves the next trade.