An index that combines market prices into one number for how strained financial conditions are; zero is average, positive is above-average stress.
Financial stress indexes take dozens of market variables, such as credit spreads, equity volatility, funding costs and demand for safe assets, standardise them and combine them. They measure what markets are pricing, not what the real economy is doing, and can spike on a single day.
worldstat.us uses the OFR's index for the United States and the ECB's CISS for the euro area.