SET is the primary equities exchange in Thailand.
Currency: Thai Bhat (THB)
The SET has two principal methods of trading: Automatic Order Matching (AOM) and Put-Through (PT).
Automatic Order Matching (AOM) trading performs the order matching process according to price, then time, priority, without human intervention. After brokerage houses electronically send buy or sell orders from their offices to the SET mainframe computer, the SET CONNECT system queues the orders and arranges them according to a price-then-time priority. This means orders are first grouped according to price, with the best price taking precedence. Then, within each price group, orders are arranged according to time.
There are two matching methods: Continuous Order Matching and Auction.
Continuous Order Matching procedures operate during the regular trading sessions. The SET CONNECT trading system continuously matches the first buy and sell orders in the queue, and, at the same time, confirms each executed transaction via the member's (broker's) terminal.
The Auction matching is utilized in calculating the opening and closing prices of a security at the opening and closing of the trading hours. This method allows brokers to enter their bid/ask orders to be queued for matching at a specified time at the price that generates the greatest trading volumes for that particular stock.
In Put Through (PT) Trading, when the trading value crosses over 10,000 units, which is equivalent roughly to 10 million Baht, an alternative method provided by TBX called “Put Through” must be selected. The counterparties can negotiate off the exchange. Once the deal is concluded, the seller can initiate the put through transaction, which then needs to be verified by the buyer. Once the confirmation process is completed, the buyer will allow that transaction to go to the next process, clearing and settlement.
|Price Range||Tick Size|
|lower than 2 Baht||0.01 Baht|
|at least 2 Baht but lower than 5 Baht||0.02 Baht|
|at least 5 Baht but lower than 10 Baht||0.05 Baht|
|at least 10 Baht but lower than 25 Baht||0.10 Baht|
|at least 25 Baht but lower than 100 Baht||0.25 Baht|
|at least 100 Baht but lower than 200 Baht||0.50 Baht|
|at least 200 Baht but lower than 400 Baht||1.00 Baht|
|400 Baht and above||2.00 Baht|
The opening auction is randomized to occur between 9:55 and 10:00 for calculating the opening price for the morning trading session. The opening for the afternoon session is also randomized to occur between 14:25 and 14:30 for calculating the opening price for the afternoon trading session.
Time to Submit LOO - 9:30 - 9:55 (14:30 for afternoon session)
The closing price is defined by the following closing auction mechanism.
Auction means an auction conducted in a trading platform in respect to qualifying orders to determine the auction price pursuant to the following process:
The SET's trading systems randomly select the closing time between 16:35 - 16:40. Therefore, members will have an extra period from 16:30 to the random closing time to place additional orders that will not be matched or executed until the random closing time. At the random closing time, the SET calculates the closing price by the Auction method, which is the same method for determining the opening price in the pre-open session. From all the valid orders in the system, the closing price will be determined from:
1. The price that generates the greatest executable volume.
2. If there is more than one such price at which there is maximum executable volume, the price with minimum unexecuted volume (“minimum imbalance” or “minimum order surplus”) will be chosen.
3. If there is more than one price in 2., the market pressure on the side of the book with the minimum imbalance decides the execution price.
The reference price will always equal the last traded price. If the stock has never traded before, the reference price is an IPO price. If there is no reference price, the highest potential auction price will be chosen.
Note: because At-the-Open and At-the-Close orders contain first-matching priority over limit price order, the system will determine the price of ATO and ATC orders as follows:
1. Morning Trading Session (09:55:00 - 10:00 - 12:30)
2. Afternoon Trading Session (14:25:00 - 14:30:00 - 16:30)
3. Pre-Close (16:30 - 16:35:00 - 16:40:00)
Order Types: Limit and Market DAY orders may be used to participate in the closing auction.