Unit Economics

The One Bad Month Stress Test

Run the single test that reveals whether your business could survive a lost customer, a supplier failure, or a sudden slump.

  • Beginner
  • 6 min total
  • 11 chapters

What decision this helps you make: How much cash cushion to hold, and which risks to fix before they arrive.

What this topic is

The one-bad-month stress test asks a simple, brutal question: if something went wrong — a lost customer, a supplier failure, a slow month — could your business survive it, and for how long?

Why it matters

Most businesses plan only for things going right. The ones that last also know their breaking point. A quick stress test turns invisible fragility into a number you can actually manage.

Who should learn it

Every owner and founder — especially anyone running lean, growing fast, or depending on a few customers, suppliers, or a single good season.

What you will understand

  • Measure your cash buffer — how long you'd last if income stopped
  • Stress-test a real shock: a lost customer, a bad month, a price spike
  • See why sticky costs make a revenue drop hit far harder
  • Decide how much cushion your specific risks call for

Prerequisites

Common misconception

"We're profitable and growing, so we're safe." Profit and growth say nothing about whether you could survive a sudden shock. Resilience is a separate question — and the only way to know the answer is to test it.