You chose: Cut back, hold the rest

The most defensible answer that day was to stay put—with a tripwire.

On 23 January, transmission and severe containment were credible warnings. But the WHO had not declared an international emergency, broad markets had barely moved, and financial damage was not yet visible. The careful response was to keep the position while deciding in advance what evidence would change your mind.

What your choice traded

This was proportionate, but early. It reduced the cost if the pathway widened while preserving some exposure if the outbreak stayed contained.

What actually happened

The health warning became financial damage.

The WHO declared a global health emergency one week later. Large outbreaks appeared outside China in February. By 11 March, the bond market was showing distress and yields and oil had fallen to roughly half their starting levels.

From 23 January to 11 March 2020, the US 10-year Treasury yield and Brent crude fell to roughly half their starting levels. The New York Fed corporate bond market distress index nearly doubled by its latest reading on 6 March.you decided11 March
Each line is set to 100 around the day you decided, so direction—not the raw units—is comparable. The corporate-bond reading is weekly and ends on 6 March. Sources: Federal Reserve H.15, US Energy Information Administration, and Federal Reserve Bank of New York.

Knowing the ending does not make selling immediately “correct.” The useful lesson is that the decision changed when the pathway widened and financial markets began confirming damage.

Try the real exercise

Make all four COVID decisions with the future hidden.

The complete trainer asks for your reason, confidence, tripwire and review date. All twelve lessons are free. No account or email is required. Your answers stay in this browser unless you later choose to save historical lesson progress online.

Continue in the complete free trainer

The organizing idea

Markets price expected financial damage—not how frightening the event sounds.

Probability is only one input. Exposure, severity, duration, policy response, and what prices have already absorbed determine the decision.

01Define the exact event
02Judge evidence quality
03Trace the economic channel
04Estimate portfolio damage
05Find first-reacting markets
06Decide what is priced
07Choose the smallest adequate action
08Predefine what changes your mind

How the practice works

Make the decision before you are allowed to know the ending.

Each lesson reveals four dated checkpoints. You record an action, a reason, your confidence, what would change your mind, and when you will look again—before anything later is shown.

Twelve complete lessons

Crises you remember—without the hindsight you have now.

Health scares, bank failures, war, trade, politics, energy and supply chains. The cases differ because frightening news and financial damage are not the same thing.

01

COVID-19

When a health warning became an economic shutdown

02

Lehman and AIG

When funding damage became systemic

03

Mpox

A global alarm without broad economic damage

04

Brexit

Severe local repricing, smaller global consequences

05

US debt ceiling

The 2011 standoff and credit downgrade

06

US government shutdown

A political shock with limited lasting damage

07

Abqaiq

The weekend oil-supply shock

08

US–China tariffs

The May 2019 escalation

09

Ever Given

When duration decided the Suez threat

10

Russia invades Ukraine

War, energy and financial contagion

11

Silicon Valley Bank

Failure, contagion and the backstop

12

Iran and Israel

Direct exchange without sustained contagion

Free to use

All twelve lessons are open to everyone.

Start anywhere and come back whenever you want. No payment, account, access code, or email address is required.

Complete trainer

Free

Your progress and answers are saved automatically in this browser. You can export them, or enter an email and choose Save progress to keep an online copy of the historical lessons.

  • All twelve lessons and 48 decisions
  • Private live-evidence guide after three core lessons
  • Explanations after each completed decision
  • No account, payment, or access code
Start the complete trainerRestore or manage progress

What this is not.

Does it tell me what to buy or sell?

No. It teaches a decision process. It never selects, sizes, authorises, or executes a trade, and gives no personalised advice.

Does it predict the next crisis?

No. Historical cases are practice material, not evidence that the next event will behave the same way.

Where do my answers go?

They stay in your browser by default. If you enter an email and choose Save progress, only historical lesson answers and checkpoint progress are copied online. Imported live evidence and private briefs never are.

Is the complete trainer really free?

Yes. Every lesson and the private live-evidence guide are free. There is no paid tier.