1. Trading time:

Orders are valid throughout trading hours. Orders unmatched, partially matched or not cancelled in the morning session are valid in the afternoon session.

2. Trading method

     - Periodical order matching method or call auction: This is a transaction method executed by the trading system on the basis of matching securities buying and selling orders at a specific time. The trading system shall conduct the comparison and matching of securities buying and selling orders on the basis of price and time precedence as follows:

a) Is the exercise price at which the maximum trading volume is reached and all buy orders with higher prices, sell orders with lower prices than the selected price must be exercised. 

b) In case there are many price levels satisfying point a of this clause, the selected price is the price at which the orders of one party must be fully exercised, the orders of the counter party must be exercised full or a part.

c) In case there are many price levels satisfying point b of this clause, the selected price is the price that is the same or close to the nearest exercise price according to order matching method.

d) In case there is no price satisfying point b of this clause, the selected price is the price that satisfies point a of this clause and coincides with or is close to the nearest exercise price according to order matching method.

      - Continuous order matching method: This is a transaction method executed by the trading system on the basis of matching securities buying and selling orders immediately upon their entry into the trading system.

3. Principles of order matching

a. Price precedence

- The buying order of higher price shall take precedence;

- The selling order of lower price shall take precedence.

b. Time precedence

- Where multiple sell or buying orders are of the same price, the order that is first entered into the trading system shall take precedence.

4. Quote unit and tick size

a. Quote unit

- Board lot: A multiple of 100 share units, closed-end fund certificates, ETF certificates and warrants - a quote unit for continuous order trading

- The maximum volume of a board-lot order placed cannot exceed 500,000 shares, closed-end fund certificates, ETF funds and warrants

- Block trade (put through trading):

• Board lot: From 20,000 shares, closed-end fund certificates, ETF certificates and warrants on wards
• Odd lot: 1 - 99 shares, closed-end fund certificates, ETF certificates and warrants 

- No quote unit is provided on put-through method and on bond trading.

- Odd lot: Odd lot trading (from 1 share to 99 shares), closed-ends fund certificates, ETF certificates and warrants

- Investors place odd lot trading via securities companies as same as board lot trading. Odd lot trading is completely separated from board lot trading, odd lot orders will only be matched with odd lot orders, not board lot orders.

- Odd lot shares trading, fund certificates and covered warrants newly listed or re-traded after being suspended for 25 consecutive trading days or more are not entered into the trading system until the closing price is established.

b. Tick size

- Order-matching method:  

- For ETF certificates and warrants: A tick size of VND10 is applied to all price ranges

- Tick size is not applied to bond trading.

5. Reference price and trading band (collar)

- Trading band for a stock in a trading day is 7% to the either side of the reference price of share/fund certificate

- Trading band is not applicable to bond transactions.

a. Daily ceiling/floor price or daily upper/lower limit price of a share, closed-end fund certificate, ETF fund certificate and a warrant is determined as follows:

• Ceiling price = Reference price + (Reference price * Ceiling trading band)
• Floor price = Reference price + (Reference price * Floor trading band)

In case the trading band or collar (± 7%) is applied, the ceiling/floor price is equal to the reference price thereof. The price adjustment is made as follows:

• Adjusted ceiling price = Reference price + a tick size of price.
• Adjusted floor price = Reference price -a tick size of price

In case adjusted ceiling/floor price of share, fund certificate is zero, the ceiling and floor prices will be adjusted as follows:

• Adjusted ceiling price = Reference price + a tick size of price
• Adjusted floor price = Reference price

- The price band of a newly listed stock, closed-end fund certificate and ETF certificate on the first trading date or suspended stock and fund certificate on the date of resumed trading shall be ± 20%. Predetermined reference price of a share on the first trading day is proposed by the issuing organization or at the advice of a consulting organization (if any) to calculate the reference price of the stock, closed-end fund certificate and ETF certificate on the first trading date. In case the reference price is not determined in the first three trading days, the issuing organization shall redefine the reference price thereof.

- The price band of a stock, closed-end fund certificate and ETF certificate suspended for trading in over 25 days is ± 20% from the predetermined reference price on the first day of resumed trading.

- The closing price on the first resumed trading day will be reference price for the following day. The price band is 7% to the either side of the reference price (except for cases carrying rights).

- In case the reference price is not determined in the first three resumed trading days, HOSE will consider redefining the reference price after it obtains permit from the SSC.

b. Ceiling/floor price on the first trading day and an ordinary trading day of call warrant based on the underlying share of a stock is determined as follows:

• Ceiling price = Reference price of warrant + (Celling price of underlying stock - Preference of underlying stock)*1/conversion ratio
• Floor price = Reference price of warrant - (Preference of underlying stock -Floor price of underlying stock)*1/conversion ratio

In case the floor price of a warrant is less than or equal to zero, the floor price shall be the smallest price unit of VND10.

- Call warrants that base on the underlying share of a stock, the reference price of the first trading date is determined as follows:

• Reference price of call warrant = Issuing price of warrant *(Reference price of the underlying stock and the first trading date of warrant/Reference price of the underlying stock on the date of issuing warrant certificate) * (conversion ratio on the date of issuing warrant certificate/Conversion ratio on the date of the first trading date)

- Where the trading is suspended for 25 days or more, the reference price of call warrant is determined as follows:

• Reference price of call warrant = Closing price of warrant and the trading day preceding the first day of trading suspension*(Reference price of the underlying stock on the first trading date of warrant after trading resumes/Reference price of the underlying stock on the preceding trading date of trading suspension) * (Conversion ratio on the preceding trading date of trading suspension/Conversion ratio on the first date the warrant resumes trading)

6. Trading orders

a. Trading orders for determining the opening price (ATO orders)

- Trading orders at the price level at which orders are matched for determining the opening price are orders to buy or sell securities at the opening price.

- ATO orders shall be given priority over limit orders (LO) while matching orders

- ATO orders shall be placed into the trading system during the periodical order matching session for determining the opening price and shall be automatically rescinded after the time of determination of the opening price if such orders are not exercised or fully exercised.

b. Limit order (LO)

- LO is an order to buy or sell securities at a predetermined price or better price. An LO shall be effective as from it is placed into the trading system until the close of the trading day or until the rescission of the order.

- Only use LO for odd lot trading.

c. Trading orders at the price level at which orders are matched for determining the closing price (ATC orders)

Procedures are the same as ATO orders but are applied at the closing (ATC) session.

d. Market order (MP)

- An order to buy or sell a stock at the best available price at the relevant time.

- Principles of order matching

• When a buy order is entered the trading system, it will be executed immediately at the lowest available price and the sell order will be executed immediately at the highest available price.
• If the quantity of such a market order is not fully filled, the market order will be the buy order at the next higher price available or the sell order at the next lower price available.
• If the quantity of market order is impossibly filled out because the counterpart orders run out, the buy market order will become a buy limit order (LO) at the last-traded price and the sell market order will become a sell limit order at last-traded price.

- Characteristics:

• MP order is applied only to continuous order-matching session.
• MP order will be cancelled if there is no corresponding order at the time of being entered into the trading system.
• Compared with an LO order, an MP is executed faster than an LO order because it is executed immediately after being placed onto the order book.

7. Order cancellation

a. In periodical order matching session:

- A trading order placed may not be rescinded or modified during the periodical order matching session that determines at-the-opening price (ATO) and at-the-closing (ATC) price (including orders transferred from the continuous order matching session).

b. In continuous order matching session

- A trading order placed shall be permitted to be amended or rescinded if the original order or the balance of the original order has not yet been executed, including order or the balance of order which was not executed during the previous session of periodical or continuous order matching

8. Payment period

9. Foreigner trading

- The amount of shares and investment fund certificates purchased from foreign investors shall be deducted from the amount permitted to purchase immediately after the purchase order is made. The amount of shares and investment fund certificates sold by foreign investors shall be added to the amount of shares and investment fund certificates permitted to purchase immediately after closing the payment of transactions (T+2).

- The selling quantity of shares and fund certificates of foreign investors is accounted to the quantity of shares that foreign investors allow to purchase immediately after the payment for the transaction is made.

- The buying order or part of the buying order of shares and investment fund certificates by foreign investors is not executed, it shall be automatically rescinded if the amount of shares and investment fund certificates permitted to purchase is no longer available and the buying order added to the trading system shall not be accepted.

- The amount of securities permitted to purchase by foreign investors shall remain unchanged if the agreed transaction is conducted between two foreign investors.

* To view HOSE’s Regulation on Securities Trading, please click here (Vietnamese edition).