Periodic Call Auction Session


What is Periodic Call Auction Session? Trading in illiquid shares: Periodic call auction session is a trading mechanism that was introduced by SEBI in the year 2013 to facilitate the trading of illiquid stocks in the equity market. SEBI has issued certain guidelines for the same, on which this post is entirely based upon.

What is an illiquid share?

For the purpose of periodic call auction, a scrip shall be classified as illiquid on a stock exchange if all the following conditions are satisfied:

  • Average daily turnover of less than Rs.2 lakhs calculated for previous two quarters
  • The scrip is classified as illiquid at all Exchanges where it is traded

Of the stocks identified as per above criteria, stocks which satisfy any of the following conditions shall be excluded.

  • Securities having average market capitalization of more than Rs.10 crores
  • Scrips where company is paying dividend in at least 2 out of last 3 years.
  • Scrips where company is profitable in at least 2 out of last 3 years, and not more than 20% of promoters shareholding is pledged in the latest quarter and book value is 3 times or more than the face value

Periodic call auction session:

All equity stocks which are classified as illiquid as per above listed criteria will be part of Periodic Call Auction Session. Each slot of periodic call auction session (PCAS) lasts for an hour starting at 9:30 am. The last session in a day ends at 3.30 pm. normally, in a day the schedule will be as follows.

PCA Session number Starting time Ending time
Session – 1 9:30 am 10:30 am
Session – 2 10:30 am 11:30 am
Session – 3 11:30 am 12:30 pm
Session – 4 12:30 pm 1:30 pm
Session – 5 1:30 pm 2:30 pm
Session – 6 2:30 pm 3:30 pm

However, SEBI has further rationalized the number of auction sessions by saying “Stock Exchange may determine the number of call auction session for illiquid stocks. However in order have minimum trading sessions and uniform closing session, there shall be at least 2 sessions in a trading day with one uniform closing session across the exchanges

Entry into the session:

Stock exchanges are responsible to identify illiquid stocks at the beginning of every quarter and move them to periodic call auction mechanism. Once these are moved to PCAS, one cannot find them getting traded in regular trading platform during the normal hours.

Exit from the session:

If the following criteria are met, Stock exchanges shall move scrips from periodic call auction mechanism to normal trading session

  • The scrip has remained in periodic call auction for at least one quarter
  • It is not classified as illiquid as per the criteria for illiquidity mentioned at the beginning of this post.

Notice to the market:

A notice of two trading days shall be given to the market, stating the entry or exit of the securities in the periodic call auction session.

Activities during each trading session:

Each Periodic Call Auction Session will be divided into following 3 activities:

  1. Order entry:

In which 45 minutes shall be allowed for order entry, order modification and order cancellation.

  1. Order matching:

In this 8 minutes shall be allowed for order matching and trade confirmation

  1. Buffer period:

Remaining 7 minutes shall be a buffer period for closing the current session and facilitating the transition to next session

What about unmatched orders?

SEBI has clarified that un-matched orders remaining at the end of a call auction session may be moved into next call auction session. Also, one should note that only limit & market order types are allowed for illiquid stocks in Periodic Call Auction Session.


In the event where maximum of buy price entered by a client  is equal to or higher than the minimum sell price entered by that client and if the same results into trades, a penalty shall be imposed on such trades

The penalty shall be calculated and charged by the exchange and collected from trading members on a daily basis. Trading members may recover such penalty from clients. The penalty so collected shall be deposited to Investor Protection Fund. Penalty for each session will be as follows:

1 0.50% of the trade value for sale and 0.50% of trade value for the buy, resulting in 1% penalty for the client on PAN basis.
2 2500 /- for the buy trade and 2500 /- for the sell trade, resulting in penalty of 5000/- for the client on PAN Basis

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