Why writing down your method changes everything

Most retail investors invest on instinct. They buy on impulse, sell out of fear, don’t remember why they hold a given line, and have no written exit criteria. Long term, what costs them isn’t the strategy — it’s the absence of one.

This article doesn’t propose a method. It defends a more fundamental act: writing one down, any one, as long as it exists on paper.

The investor without a method

You probably know this profile — maybe yourself a few years ago:

Three positions opened at random in late 2019. Nice paper gain in February 2020. Panic in March: everything sold at −30%. Index rebounds in a few months, back to highs by June 2021: re-bought on FOMO. Another correction in 2022: sold again, at a loss again.

The problem here isn’t timing or stock picking. The problem is that no decision had a pre-existing criterion. Each action was a reaction to the emotion of the moment, with no framework to push back.

The investor without a method can be technically brilliant. They know ETFs, fees, taxes, valuations. But under stress, they do the opposite of what they know. And that’s normal: their brain, in that moment, has no access to what they know calmly.

Three things a written method does, that you under stress don’t

A written method doesn’t make you smarter. It does three things for you, at the moment you can’t.

1. It remembers. In March 2020, you no longer remember why you bought this position. Your method does: “I bought X because Y, I exit at Z”. That external memory is what holds you when emotion clouds your internal one.

2. It defuses the bias of the moment. “I should have sold earlier”, “I should have bought the dip”, “everyone says it’s going back up”: noise. A pre-established rule (“I rebalance if drift to target exceeds 5 points”) short-circuits the noise. Not perfectly — but far better than nothing.

3. It improves by iteration. A written method can be criticized off-market, calmly, by re-reading the decisions it produced. A method in your head can only be defended — it shifts constantly, without you noticing, to stay compatible with what you actually did.

A method isn’t a system

Many beginners confuse the two and give up before starting: “I don’t have the skills to code a system, so I have no method”. False. A method can fit in six lines. A system starts where the method ends — and 95% of retail investors don’t need one.

The minimal skeleton

Six blocks. Fill in what you know today — you’ll come back to it. One month of thinking per block is over-engineering; one hour is enough for a first version.

1. Goal — amount and horizon. "€80,000 over 15 years" beats “get rich”.
2. Target allocation — % per asset class. “60% stocks / 25% bonds / 15% cash” is a decision; “I buy whatever goes up” isn’t.
3. Entry rule — when you deploy capital. Monthly DCA? Market threshold? Lump sum at account opening? Pick one, write it.
4. Exit / rebalancing rule — when you take profits, when you readjust. “Rebalance if a class drifts more than 5 points from target” is executable. “I’ll sell when it’s gone up enough” isn’t.
5. Pause trigger — “I suspend if…”. Job loss, imminent home purchase, birth, divorce. Defining the pause in advance lets you actually pause without guilt.
6. Review date — semi-annual or annual. Put it in your calendar now. A method never re-read expires.

That’s it. No “macro thesis” section, no “bear case / bull case” — you’ll add those if you need them in six months.

The “I don’t know yet” objection

The most common one, and exactly the reason to write. If you already knew, you wouldn’t need to externalize. You write what you know today — knowing it’ll be incomplete, uncertain, partly wrong. Version 1 is supposed to be mediocre.

A method isn’t a final exam, it’s a living draft. A rule that seemed good today and cost you last year: you fix it at the next review. That’s how it improves — not by sitting in your head silently mutating.

The article How I actually run my portfolio (on the backlog) will show a real version 3, scars included.

The “it removes flexibility” objection

Confusion between flexibility and improvisation.

• Flexibility: you can modify your method between reviews, but you write down the change (date, reason, new rule). You keep the trail.
• Improvisation: you do whatever you want whenever you want, no trail, justifying after the fact. That’s what the investor without a method does.

Mostly, a written method lets you say no. The market floats 10 ideas a month at you; your method lets you reject 9 without internal debate. That’s the freedom you gain — not the freedom to buy, the freedom not to cave.

The review ritual

Every useful method I’ve seen shares a review ritual. Not daily, not monthly: semi-annual is a good default.

Thirty minutes, four questions:

1. What worked? (Not in performance — in adherence to the method.)
2. What didn’t? (Decision taken outside the rules, rule ignored, bias identified.)
3. Any rule to modify? (If yes, dated version.)
4. Any rule to remove? (Often forgotten — a rule unapplied for six months is probably dead.)

During the review, a glance at the macro context (inflation, rates, yield curve) helps adjust the target allocation if the market regime has clearly shifted. But not for the sake of moving: this is a review, not a rewrite.

Conclusion

A mediocre written method beats any perfect method stuck in your head. Like keeping a mediocre journal beats not writing at all: what matters is the gesture, the externalization, the traceability.

If you’ve read this far without a written method, this week’s action is simple: take a sheet (or a file), write the six blocks above, fill them with what you know. You’ll have a version 1. That’s all we’re asking.

Going further

This manifesto is the gateway to the method topic. Upcoming articles:

• How I actually run my portfolio — version 3 of a real method, tools, rituals.
• DCA vs lump sum: what the studies actually say
• Allocation by horizon (5 / 10 / 20 years)
• Build your emergency fund before investing
• Five cognitive biases that cost you — direct cross-ref with the psychological risk covered in Bitcoin series, article 5
• Reading an annual report in 30 minutes
• Backtesting isn’t predicting

And if you haven’t read the sibling manifesto, Why macro matters is its counterpart: macro illuminates the context, method executes within it. One without the other goes in circles.