How to write down investment decisions

Published 2026-05-18 - Updated 2026-08-26

A useful decision note is short, specific, and written before the outcome can make the decision look obvious.

Short answer

Write the decision type, the reason, the evidence, the risk, and the review trigger in plain language.

Name the decision type

Buy, hold, add, trim, exit, watch, and pass are different decisions. Naming the type keeps the note clear.

Use one reason, one risk, one trigger

Decision notes should be easy to reread. Long essays are less useful than a clear reason and a clear review condition.

Connect decisions to thesis status

The decision should say whether the thesis is intact, strengthening, weakening, broken, or still unknown.

Practical checklist

• Decision type and date.
• Ticker and intended action.
• Main reason.
• Evidence and saved source.
• Risk or disconfirming signal.
• Review trigger.

Example decision note

Fictional sample only: a watch decision after reading an earnings call.

• Decision: keep on watchlist, no buy yet.
• Reason: thesis is plausible, but customer concentration is still high.
• Review trigger: revisit after annual filing if concentration falls below 30%.

Mistakes to avoid

• Writing only the action and not the reason.
• Using confidence without evidence.
• Forgetting to record why you chose not to act.