Additional surveillance measure

A framework under which exchanges place unusual securities under heightened surveillance, applying stricter margin requirements and sometimes restricting trading to a periodic call auction.

Placement is driven mainly by price and volume behaviour, though the long-term framework also screens on valuation measures such as the price-to-earnings ratio, so it flags the market's behaviour and makes no finding about the company's honesty. Exchanges run a separate graded surveillance framework built around the company's fundamentals.

For an investor the consequences are practical. Margins rise and liquidity thins, and exiting a position gets harder.

A stock that has been under surveillance repeatedly deserves an explanation before you let capital go near it.