What this actually is
A disease outbreak large enough to change behaviour at scale. Economically it is unique because it removes supply and demand at the same time — people cannot work and will not buy.
Why it matters to a person
2020 established the playbook: shut down, then pay households and businesses directly, then cut rates to zero and buy bonds. That combination produced the fastest bear market and the fastest recovery on record, and the inflation of 2021–23.
For scale
The S&P 500 fell 34% in 23 trading days and regained the loss within five months. The unresolved question is whether the same fiscal and monetary response would be politically available a second time.
How to read a release
Reading it
Watch case severity rather than case counts, and watch whether governments impose restrictions or leave them to individuals — the economic damage follows policy more than the virus.
The mechanism
The only shock that stops demand and supply at once; produced both the fastest bear market and fastest recovery on record.
What to watch: WHO disease outbreak news. Arrives event; the effect typically lasts months. Impact tier 1 — Regime-setting: Moves everything and sets the direction for months or years. These are the discount rate, the level of earnings, the availability of credit, and the shocks large enough to stop the economy. If one of these turns, nothing else in the list matters much.
Its neighbourhood
Everything this entry connects to directly. Click any point to follow it.
What it moves next
Documented transmission: when this moves, these tend to move after it.