What it is
When a stock moves abruptly, VI replaces continuous trading with a two-minute single-price auction to give investors time to react.
Types
Dynamic VI triggers when the price moves beyond a set range from the last trade (the range depends on the stock and session). Static VI triggers on a move of 10% or more from a base price such as the previous close.
What to keep in mind
A VI means orders suddenly piled up on one side, often alongside news or a filing. Prices sometimes reverse once the VI ends, so be careful chasing the move.
This explanation is general information, not investment advice. Rules reflect September 2026 and may change; check official exchange and broker notices.