What does GSM mean?
GSM stands for 'Graded Surveillance Measure'. In order to enhance market integrity and safeguard the interest of investors, Securities and Exchange Board of India (SEBI) and Exchanges, have been introducing various enhanced surveillance measures such as reduction in price band, periodic call auction and transfer of securities to Trade to Trade segment from time to time.
There are 4 stages of surveillance actions as shown in the image below:
Stage II has an Additional Surveillance Deposit (ASD) of 50% of the trade value which is what reflects in your ledger.
This amount will be released based on the following table:
Also, check out these posts on TradingQ&A for more information.