Catalyst
A scheduled or expected event that could move a company's share price, such as earnings, an approval or a product launch.
In trading, a catalyst is an event that may change the price of a security. Catalysts can be scheduled, such as earnings, a central bank decision or an index review, or unscheduled, such as a court ruling or a deal announcement. Confirmed catalysts have a date and a source; expected ones are estimates.
On our site, catalysts are listed with an expected date, a confirmed flag and the linked companies. Treat an unconfirmed date as a planning estimate.
Traders care because positioning often builds ahead of a catalyst, and the surprise relative to expectations determines the move. A catalyst that does not surprise can produce little reaction.
Worked example (illustrative numbers, not real data): a drug company's regulatory decision is expected in the second half of the month, with the exact date not yet confirmed. Options traders may bid up implied volatility for that window, and the stock may move sharply on the decision whichever way it goes.