Why I Write Before I Buy: The Pre-Trade Note That Saved Me $40,000

February 2021. I'm watching a retail brand trading at $14 — a company I knew nothing about, had never researched, and had no opinion on three days earlier. But the stock had been up 40% in four days, it was all over financial Twitter, and everyone I followed seemed to be printing money on it.

I told myself it was a "quick trade." In and out. I didn't need a thesis for that — just momentum. I bought $47,000 worth of shares at $16.40 and watched it go to $19 the next morning. Then it reversed. Then it kept reversing. I held because I didn't have a thesis to check against. I had nothing to tell me when I was wrong. Seven weeks later I sold at $9.30.

The loss was $40,000. The actual cost was the lesson.

What a Pre-Trade Note Is

Since that February, I write a note before every single trade. Not after I decide. Before. The note doesn't have to be long — the median length is 180 words. But it has to contain five specific things, in order.

If I can't write all five in under three minutes, I don't enter the trade. That's the rule. If I can't articulate it in three minutes, I don't understand it well enough.

The Five Elements

1. The thesis in one sentence.

Not a paragraph. One sentence. "This company is a toll-booth business in a market growing 20% annually, trading at a 30% discount to its five-year average forward multiple."

The one-sentence requirement is deliberately brutal. It forces clarity. Most bad trades can't survive this step — they collapse into "it's been going up" or "I heard about it from someone I trust." Those aren't theses. They're hope.

2. What kills the thesis.

Specific, observable events that would make the thesis wrong. Not "if the stock goes down." Stock price is not a thesis killer — that's just price discomfort. Real killers are things like: management turnover in the key function, margin compression in consecutive quarters, a regulatory ruling against the core business model, a new entrant capturing share in the primary segment.

I once wrote: "Thesis breaks if the gross margin drops below 58% for two consecutive quarters." That sentence saved me. When Q3 margin came in at 56.1% and Q4 at 55.3%, I had a written instruction to exit. I didn't need to decide anything in real time. The decision had already been made.

3. Three exit scenarios.

Every position has three possible outcomes: it works, it stalls, or it blows up. I write a plan for each.

Exit 1 (thesis plays out): At what price or metric achievement do I take partial profits or full exit? This prevents me from riding a winner to zero by overstaying.

Exit 2 (thesis is unclear): If the business is neither clearly improving nor clearly deteriorating after twelve months, I exit and redeploy capital. Opportunity cost is real.

Exit 3 (thesis is broken): Specific trigger (see element 2 above). When that trigger fires, I exit without reconsideration.

4. Position size and why.

This forces me to connect my conviction to my allocation. If I'm writing "5% position because the outcome is binary and I can't model the range," I've just caught myself taking a speculative position at a core-position size. The writing catches contradictions that the trade idea alone doesn't surface.

5. Time horizon.

One month? Six months? Five years? This matters more than most investors acknowledge, because it defines what evidence is relevant. A trade thesis with a two-week horizon doesn't get shaken by a bad monthly employment print. A five-year thesis doesn't get shaken by a quarterly earnings miss that was timing-driven.

Matching your time horizon to your evidence-gathering prevents the worst category of error: using long-term thesis to rationalize holding a short-term trade that's going against you.

How It Prevented the Next FOMO Trade

Three months after the February loss, I saw another situation — a cloud infrastructure company with strong momentum, heavy social media volume, and a compelling growth narrative. I sat down to write the pre-trade note.

I couldn't finish element 1. I wrote: "This company is growing fast and the market is big." That's not a thesis. I tried again. "This company has a first-mover advantage in..." — but when I checked the market share data, they were third, not first. The note fell apart in the writing.

I didn't take the trade. The stock ran another 30% over the next four months. And then it dropped 65% over the following year. I didn't know that would happen when I skipped it. But I did know that I didn't have a thesis. That was enough.

The Exit Moment

The other place the note earns its keep is at the exit — when you're down 15% and wondering whether to hold or cut.

Without a note, the decision becomes entirely emotional. With a note, it becomes a review process: Has element 2 (the thesis killer) fired? If no — hold. If yes — cut.

I've reread pre-trade notes at 2am when a position was down 18% and I was convinced the world was ending. The note said the thesis was intact. I held. In several cases, the position recovered. In others, the thesis eventually did break and I exited then — but on my terms, not from panic.

The Three-Minute Rule

If you can't write a coherent pre-trade note in under three minutes, you don't understand the trade. That's not a harsh judgment — it's a diagnostic. Most legitimate investment ideas can be stated simply. Complexity in the explanation usually masks uncertainty in the thinking.

The rule has one corollary: if you're under time pressure to enter before the note is complete, the urgency is the red flag. Real investment opportunities don't require that you skip your process. If you miss a trade because you took four minutes to write a note, you missed a trade. You didn't miss the only trade that would ever exist.

Write it first. Every time.

— Ruslan Averin