Most trading journals are abandoned within weeks. The usual cause is length. A scalp can be over in minutes, and a journal entry that takes longer than the trade does not get written. Three lines per trade is a format that can keep pace.
Line one, before the order
The reason, in one sentence, written before the order is sent. It names the level, the regime and the condition. Price at the put wall, above the flip, first test of the session. If the sentence cannot be written, there is no trade to take. This line also gives the exit rules something to be checked against, as in the thesis exit.
Line two, at the fill
What was done. The time, the strike, the price paid and the quote at that moment. The difference between the quote and the fill is the entry’s cost, and it is only visible if both are written down. The gap between a signal and a fill explains why that difference deserves a record of its own.
Line three, after the exit
How it ended and which rule ended it. Target, price stop, time stop, thesis exit or scratch. The exit type matters more than the result. A profitable trade closed by no rule at all is a different entry from a profitable trade closed at its target.
What three lines leave out
Screenshots, feelings and long reviews. All of them have value, and keeping a trading journal makes the case for the fuller version. They can be added at the end of the day to the trades that deserve them. The three lines are the part that has to be written at the time, because memory of a fast trade is poor an hour later.
What they show over weeks
Read down line one and the same few reasons repeat. That is the trader’s real playbook, which may differ from the intended one. Read down line three and the mix of exit types appears. Set line one beside line three for any trade and the question is whether the exit matched the reason.
The numbers a longer record supports are covered in trading journal metrics. The three lines are the raw material for them.
A day without a setup gets one line: what was looked for and why it did not appear. Journaling the trades not taken explains why those entries matter.
A shared vocabulary
Line one is easier to write when the terms are fixed. Trader shows net GEX, the gamma flip, the walls and the expected move on SPY, QQQ and IWM, so a reason can be written in those words and checked against the same screen afterward.