Field notes

How indicators are built, tested, and sold.

No hype, no signal-of-the-day. Just the honest mechanics — how to tell a validated edge from a curve-fit backtest, and what to check before you trust any tool with your risk.

Articles

Buying an indicatorJuly 13, 2026 · 6 min

How to spot a curve-fit indicator: 5 questions before you buy an algo

Most indicators look flawless in the screenshot and fall apart live. Curve-fitting is usually why. Five questions that cut through the marketing before you pay.

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How it worksJuly 13, 2026 · 6 min

What “non-repainting” really means — and how to check any indicator yourself

“Non-repainting” is the most abused word in indicator marketing. Here's what it actually means, why it matters, and how to verify it on any script in minutes.

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MethodologyJuly 13, 2026 · 6 min

Why a perfect backtest means nothing: in-sample vs out-of-sample

A flawless backtest is the easiest thing in the world to produce. Here's the one distinction — in-sample vs out-of-sample — that separates a real edge from a memory of the past.

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Reading the numbersJuly 22, 2026 · 5 min

Why win rate is a vanity metric — and what to look at instead

A 92% win rate can still lose money. Why win rate flatters, the math it hides, and the two honest numbers — profit factor and expectancy — that actually tell you if an edge exists.

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Trading disciplineJuly 13, 2026 · 5 min

The best trade is often no trade: how a regime filter beats overtrading

The most expensive habit in trading is trading when there's nothing to trade. Why markets punish activity, and how a regime filter turns “stay out” into an edge.

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