Trading regulations at HSX (Ho Chi Minh Stock Exchange)

1. Trading Hours
Trading occurs Monday through Friday each week, except on public holidays as defined by the Labor Law or decisions by the State Securities Commission of Vietnam.
1.1. For Stock Trading, Closed-end Fund Certificates, Exchange-Traded Fund, and Warrant Certificates with collateral:

Trading Session	Time	Trading Method
	9h00 – 9h15	Opening Period Regular Matching Orders ATO, LO Negotiated Deals
Morning session	9h15 – 11h30	Continuous Matching Orders LO, MP Negotiated Deals
Lunch Break	11h30 – 13h00
Afternoon session	13h00 – 14h30	Continuous Matching Orders LO, MP Negotiated Deals
	14h30 – 14h45	Closing Period Regular Matching Orders ATC, LO Negotiated Deals
	14h45 – 15h00	Negotiated Deals

1.2. Bonds:

Negotiated trading occurs from 9h00 to 15h00, with a break from 11h30 to 13h00.
2. Matching Methods:

A. Types of trading orders:
i. Opening Price Matching Orders (ATO):

• An order to buy or sell securities at the opening price. ATO orders have priority over limit orders when matching trades.
• During the regular opening price matching session, the trade price cannot be determined if there are only ATO orders in the order book.
• The order will be automatically canceled at the end of the session if the order is not executed or not fully executed.

ii. Limit Orders (LO)

• A buy or sell order for securities at a specified or better price, effective from the time of entry into the trading system until the end of the trading day or until canceled.

iii. Market Price Orders (MP)

A buy order at the lowest selling price or a sell order at the highest buying price currently available in the market during the continuous matching session. MP orders have the following characteristics:

• MP orders are cancelled if there is no corresponding limit order at the time of order entry into the system.
• Compared to limit orders, MP orders have a higher likelihood of being executed quickly as they are immediately matched when entered into the order book.

iv. At-the-Close (ATC) Order:

• An order to buy or sell securities at the closing price. ATC orders are given priority over limit orders when matching trades.
• During the regular closing price matching session, the trade price cannot be determined if there are only ATC orders in the order book.
• The order will be automatically canceled at the end of the session if the order is not executed or not fully executed.

B. Trading Methods:

– Periodic call auction: being performed on the basis of securities matching buy and sell orders at a specified time.

+ The price determination principle is based on achieving the highest trading volume. If multiple prices meet this condition, the price closest to the execution price of the last matching order will be selected.

+ In periodic call auction sessions, orders cannot be modified or canceled.

– Continuous auction: a trading method made on the basis of matching buy and sell orders as soon as they are entered into the trading system.

– Negotiation auction: Buyers and sellers can negotiate one-on-one deals and then notify a securities company to record the transaction results in the trading system. Alternatively, buyers or sellers can engage a securities company to find a counterparty for a reciprocal agreement.

* Note: On the first trading day of newly listed/registered securities or the first trading day after a stock has not been traded for 25 consecutive sessions, negotiated trading orders are not executed until a reference price is established based on the results of continuous matching.

3. Matching Principles:

– Price Priority: Orders with better prices (higher buy orders, lower sell orders) are given priority for execution.

– Time Priority:

• Buy or sell orders with the same price are executed in the order of their entry into the system.
• In the continuous matching session, if buy and sell orders meet the price condition (Buy Price ≥ Sell Price), the matching price is the price of the order entered into the system first.

4. Trading Units and Price Quotations

A. Trading Units:

– The trading unit (even lot) for matching orders is 100 shares/closed-end fund certificates/ETF fund certificates/warrants.

– Each even lot trading order cannot exceed the maximum volume of 500,000 shares/closed-end fund certificates/ETF fund certificates/warrants.

– Negotiated trading volume: from 20,000 shares/ETF fund certificates/closed-end fund certificates/warrants and above; no specific trading unit is specified.

– Odd lot trades (from 1 to 99 shares/ETF fund certificates/closed-end fund certificates/warrants) can be executed through continuous matching or negotiated trading.
(Note: Odd lot matching trading time is from 9h15 to 11h30 and from 13h00 to 14h30; odd lot negotiated trading time is from 9h15 to 11h30 and from 13h00 to 15h00)
– The trading unit for bonds is: 1.

B. Price Quotations:
– For matching orders

Price Range	Stock (Listed Stocks)	ETF Fund Certificates/Warrants (Listed)	Negotiated Bonds
<10,000 VND	10 VND	10 VND	Not specified
10,000 VND – 49,950 VND	50 VND	10 VND	Not specified
>=50,000 VND	100 VND	10 VND	Not specified

5. Reference Price and Price Fluctuation Range

A. Reference Price:

– The reference price for stocks and ETF fund certificates is the closing price of the most recent trading day (the last matched price in the previous trading day).

– The determination of the reference price for newly listed stocks and ETF fund certificates on the first trading day is proposed by the listing organization, fund management company, and listing advisory organization (if applicable). If, within 3 consecutive trading days from the first trading day, the price for the next trading day cannot be determined as the reference price, the listing organization, fund management company, and listing advisory organization (if applicable) must reassess the reference price.

– In the case of stocks and ETF fund certificates entitled to dividends and/or accompanying rights, the reference price on ex-dividend trading day is determined by taking the closing price of the most recent trading day adjusted for the received dividend value or the value of the accompanying rights.

– The reference price will not be adjusted in cases where a company issues convertible bonds or additional shares at a higher issuance price than the average price of the consecutive trading days prior to the ex-dividend date (after adjusting for other rights if applicable).

– In the event of a temporary suspension of trading for a security for 25 sessions, when trading resumes, the reference price will be determined by the Ho Chi Minh Stock Exchange (HSX) after approval from the State Securities Commission (UBCKNN).

B. Price Fluctuation Range:
i. For Stocks/Closed-end Fund Certificates/ETF Fund Certificates:

-The price fluctuation range for stocks/ETF fund certificates in a trading day with listed securities is ±7% (compared to the reference price).
-The price fluctuation range is ±20% compared to the reference price and is applied on the first trading day for newly listed stocks/ETF fund certificates or the first trading day after a stock has been suspended from trading for 25 trading days.
– Ceiling/Floor Price:

• Ceiling Price = Reference Price x (100% + Fluctuation Range)
• Floor Price = Reference Price x (100% – Fluctuation Range)

For stocks with a ceiling/floor price after adjusting the ±7% fluctuation range, but the ceiling/floor price remains the same as the reference price, the adjustments are as follows:

• Adjusted Ceiling Price = Reference Price + Minimum Price Increment
• Adjusted Floor Price = Reference Price – Minimum Price Increment

– The closing price on the first trading day after resumption of trading will be the reference price for the next trading day (except for cases where stocks have generated rights affecting the stock price). The ±7% price fluctuation range will be applied to the next trading day.
– If, within the first 3 days after resumption of trading, a stock or fund certificate still does not have a closing price, HOSE will consider adjusting the price fluctuation range for the stock or fund certificate after approval from the State Securities Commission.

ii. For Warrants (call warrants based on underlying stocks):

• Ceiling Price = Warrant Reference Price + (Underlying Stock Ceiling Price – Underlying Stock Reference Price) x 1/conversion ratio
• Floor Price = Warrant Reference Price – (Underlying Stock Reference Price – Underlying Stock Floor Price) x 1/conversion ratio

– In the case where the warrant’s floor price is less than or equal to zero (0), the floor price will be the minimum tick size of 10 VND.

– For call warrants based on underlying stocks, the reference price on the first trading day is determined as follows:

• Call Warrant Reference Price = Warrant Issuance Price x (Underlying Stock Reference Price and First Trading Day of the Warrant / Underlying Stock Reference Price at the warrant issuance announcement date) x (Conversion Ratio at the warrant issuance announcement date / Conversion Ratio on the first trading day).

– For call warrants, the reference price on the first trading day after being suspended from trading for 25 trading days is determined as follows:

• Call Warrant Reference Price = Closing Price of the Call Warrant on the trading day immediately preceding the suspension of trading x (Underlying Stock Reference Price on the first trading day of the warrant after resumption of trading / Underlying Stock Reference Price on the trading day immediately preceding the suspension of trading) x (Conversion Ratio on the trading day immediately preceding the suspension of trading / Conversion Ratio on the first trading day of the warrant after resumption of trading).

6. Placing Trading Orders:

– It is allowed to simultaneously place both buy and sell orders for the same type of security during continuous matching sessions. (Note: Same-side buy and sell orders will not be cross-matched.)
– It is not permitted to place buy and sell orders for the same type of security simultaneously within the same regular matching session, except for orders that have been entered into the securities trading system in the previous trading session, remain unmatched but are still valid.

7. Canceling and modifying matched trading orders:

– Only unmatched orders during continuous matching sessions can be canceled or modified.

– The priority order of the order on the exchange will be maintained if the modification only reduces the order quantity.

– The priority order is calculated from the time the modification order is entered into the system for cases of increasing order quantity and/or modifying the price.

8. Canceling and modifying negotiated trading orders:

– Orders can only be canceled or modified if they have not been confirmed.
– During trading hours, if the company enters the wrong negotiated trading order of an investor, the company is allowed to modify the negotiated trading order but must present the investor’s original order, and the modification must be agreed upon by the counterparty and approved by the Stock Exchange.

9. Special transactions:

– Transactions involving the purchase and sale of mutual fund shares, market-making transactions by market makers must adhere to the specific regulations outlined in Circular 120/2020/TT-BTC issued by the Ministry of Finance.

– Transactions carried out by major shareholders, internal shareholders, and related persons must comply with the specific provisions of the Securities Law and Circular 96/2020/TT-BTC issued by the Ministry of Finance.