Notice No.   20130402-7   Notice Date   02 Apr 2013
Category   Trading   Segment   Equity
Subject   Introduction of Periodic Call Auction Session for Illiquid Scrips – Trading Rules


This is in continuation to the SEBI circular, dated February 14, 2013, circular no. CIR/MRD/DP/ 6/2013 and Exchange circulars, no. 20130219-7 dated February 19, 2013 & 20130328-12 dated March 28, 2013. The Exchange is introducing Periodic Call Auction sessions for illiquid scrips with effect from Monday, April 8, 2013.
Trading Sessions
Periodic call auction sessions of one hour each shall be conducted daily throughout the trading hours with the first session starting at 9:30 am and last session ending at 3.30 pm as per details given below –

Session No.
09:30 am
10:30 am
10:30 am
11:30 am
11:30 am
12:30 pm
12:30 pm
1:30 pm
1:30 pm
2:30 pm
2:30 pm
3:30 pm

Each periodic call auction session shall consist of two periods as follows -

Order Entry Period
45 minutes
Order Entry/Modification/Cancellation Allowed
Random stoppage between 44th and 45th minute (system driven)
Dissemination of Indicative Price, Cumulative Buy & Sell quantity
Order matching and Trade Confirmation Period including Buffer period (upto 7 minutes)
15 minutes
Order matching, trade confirmation
Order Entry/Modification/Cancellation NOT Allowed
Buffer Period -  To facilitate transition between two call auction sessions

Additional Information on sessions
Ø Periodic call auction sessions for illiquid scrips shall run concurrent with continuous trading session for all other scrips not classified as illiquid.
Ø Continuous trading and post closing sessions shall not be available for these illiquid scrips.
Order Management
Ø Limit and market orders shall be permitted.
Ø All retention types shall be allowed.
Ø Stop loss orders and basket order entry facility shall not be allowed for the illiquid scrips.
Ø Odd Lot trading facility for the illiquid scrips shall be available.
Ø Trading facility for institutional series, i.e. 6 lac series range (e.g. scrip code 632715) and QFI series, i.e. 4 lac series range (e.g. scrip code 432715) shall be available for the illiquid scrips.
Treatment of Unmatched orders
All unmatched orders at the end of the every PCAS session shall be purged.
Order Matching & Equilibrium Price Computation
The equilibrium price computation shall follow the same volume maximization logic based on aggregated demand & supply of orders, which is currently followed for the pre-open and Special pre open (SPOS) sessions. For details and example on the volume maximization logic, kindly refer Exchange circular 20101014-8, dated October 14, 2010 regarding Introduction of Call Auction in Pre-Open Session.
Information dissemination
The following information shall be disseminated to the market at regular intervals during the order entry period of each PCA session as part of the market picture broadcast –
Ø The indicative equilibrium price + next best 4 bids and offers. If the indicative equilibrium price is not determined, then the best bids and offers shall be displayed.
Ø The cumulative quantities at each of these price points.
Ø Indicative equilibrium price shall be populated in the newly introduced ‘Indicative Price’ field.
Ø Indicative matchable quantity at the indicative equilibrium price shall be populated in the ‘Indicative Qty’ field.
Ø If the indicative equilibrium price/matchable quantity are not available then these fields shall be left blank.
Ø LTP: Last equilibrium price discovered. If no equilibrium price has been discovered, then the field shall be left blank.
Ø Total buy /sell depth of the book shall be populated in the ‘Buy /Sell depth’ fields.
Ø Open, High, Low and Close prices for any particular scrip shall be disseminated based on the discovered equilibrium prices during any trading day.
Price Bands
A maximum price band of 20% shall be applicable on the scrips through the day. Exchanges may reduce the price bands uniformly based on surveillance actions from time to time.
Risk Management
Risk management process shall be similar to that followed in other call auction sessions.
Market wide index circuit breaker
Following action shall be initiated in case of market-wide index circuit breaker –
Ø If triggered during order entry period of any periodic call auction session, that session shall be cancelled and all orders shall be purged.
Ø If triggered during order matching period of any periodic call auction session, the matching process shall be completed for scrips whose equilibrium price has been discovered or is in process of getting computed. For rest of the scrips, matching process shall be halted.
Ø Periodic call auction session shall be resumed at the next nearest call auction after the normal market resumes.
In case of any queries or further clarifications on the circular, trading members may get in touch with their respective Relationship Manager or the Helpdesk as per the following contact details -  
Help Desk: 022-6136 3100 (hunting)/  
For and on behalf of BSE Ltd.,

Devika Shah
Tejash Somaiya
Sr. General Manager
Asst. General Manager
Trading Operations
Trading Development

April 2, 2013