What is periodic call auction & why are some stocks traded in this category?
Periodic Call auction was introduced by SEBI in 2013 to curb volatility in illiquid stocks. Stocks that qualify the criteria of illiquidity is explained in this SEBI circular such as the average daily number of trades of less than 50, the daily trading volume of less than 10000, and a bunch of other such conditions.
There will be 6 call auction sessions conducted in a day starting from 9.30 AM of 1 hour each. The call auction window for trading is similar to the pre-market session conducted for equity stocks. There will be a 45-minute window for order placement, modification and cancellation. All orders are accepted and matched in the next 8 minutes, and trades are confirmed. There will be a 7-minute buffer period before the next call auction session.
|Session No||Start Time- Order Placement||Order Matching||Buffer Period|
|1||9:30 AM- 10:15 AM||10:15 AM- 10:23 AM||10:24 AM to 10:30 AM|
|2||10:30 AM- 11:15 AM||11:15 AM- 11:23 AM||11:24 AM to 11:30 AM|
|3||11:30 AM- 12:15 PM||12:15 PM- 12:23 PM||12:24 PM to 12:30 PM|
|4||12:30 PM- 1:15 PM||1:15 PM- 1:23 PM||1:24 PM to 1:30 PM|
|5||1:30 PM- 2:15 PM||2:15 PM- 2:23 PM||2:24 M to 2:30 PM|
|6||2:30 PM- 3:15 PM||3:15 PM- 3:23 PM||3:24 PM to 3:30 PM|
If the idea is to buy or sell such illiquid stocks, which are on periodic call auctions, the orders must be placed in the first 45 minutes, and the client will be able to buy or sell based on if the order matches in the next 8 minutes.
Refer to this NSE circular & this BSE circular for a more detailed explanation.