Mental Models & PsychologyIntermediate📖 7 min read

The 90/90/90 Rule

Why most beginners lose fast — and what to do instead.

Primary failure mode
Too much risk per trade
Second failure mode
No exit plan under stress
Hidden leak
Costs + slippage compound fast
Rookie objective
Survive long enough to learn

The "90/90/90" rule is a harsh heuristic: many new traders lose most of their capital quickly. The root cause is rarely intelligence. It is usually position sizing, leverage, and emotional sequencing (what you do after a loss).

Table of Contents

Why the Rule Exists

Position Sizing
How large a bet you place relative to your account. If sizing is wrong, even a good idea can bankrupt you.
Misread #1: "I just need a better strategy"
Misconception
Losses come mainly from not finding the right indicator or entry.
Better Frame
Most blow-ups come from risk per trade and leverage. A mediocre strategy with controlled sizing can survive; a good strategy with reckless sizing cannot.
Misread #2: "Averaging down will fix it"
Misconception
If I add more, my average price improves and I recover faster.
Better Frame
Averaging down while wrong increases exposure when your signal is already failing. In a trending loss, it is a path to forced liquidation.

A Survival-First Playbook

Rules that keep you in the game

  • Define an exit before entry: invalidation level, not hope.
  • Keep risk per trade small enough to take multiple losses.
  • Avoid revenge trades after a loss; step away and review.
  • Measure results after costs: fees and slippage matter.
Checkpoint
Which change most directly reduces the chance of ruin for a beginner?

Key Takeaways

1

Early-stage trading is about survival, not hero returns.

2

Most accounts fail from sizing and sequencing, not IQ.

3

Control leverage, define exits, and limit risk per trade.

Related Terms

Apply This Knowledge

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