Additional Surveillance Measures” (ASMs) are a set of rules and procedures implemented by stock exchanges to monitor and regulate the trading activity of certain stocks. The goal of ASMs is to prevent market manipulation, fraud, and other forms of market abuse, and to ensure the fair and efficient functioning of the stock market.

ASMs are typically applied to stocks that are considered to have a higher risk of market abuse, such as those with a high level of volatility, low liquidity, or a history of unusual trading activity. The specific measures can vary depending on the exchange and the individual circumstances of each stock, but they may include restrictions on short selling, increased reporting requirements, circuit breakers, and the imposition of penalties for violations.

In addition to protecting investors and ensuring market integrity, ASMs can also help restore confidence in the stock market and prevent significant disruptions to trading activity. Stock exchanges may periodically review and adjust the ASMs as necessary to reflect changes in market conditions and to ensure that they remain effective in preventing market abuse.

To conclude, Additional Surveillance Measures are a set of rules and procedures implemented by stock exchanges to monitor and regulate the trading activity of certain stocks and to prevent market manipulation, fraud, and other forms of market abuse.