HSX trading regulations

1. Call auction: A trading method performed by the system on the basis of matching buy and sell orders of securities at a specified time. Principles for determining price are as follows:

• Buy orders with higher prices are given priority to be executed first.
• Sell ​​orders at lower prices are prioritized for execution first.

• In case the buy or sell orders have the same price, the order entered into the trading system first will be given priority for execution.

– Stocks, closed-end fund certificates

– ETF fund certificates, warrants: apply 10 VND quote unit for all prices
– The quoted price unit for put-through transactions is 1 VND

– The prescribed price oscillation amplitude during the day for trading stocks and closed-end fund certificates, ETF fund certificates, and warrants is ± 7% compared to the reference price.
– The ceiling/floor price on the trading day of stocks, closed-end fund certificates, and ETF fund certificates is determined as follows:
Ceiling price = Reference price + (Reference price x Ceiling price fluctuation range)
Floor price = Reference price – (Reference price x Floor price fluctuation range)
– The ceiling/floor price of warrants is determined as follows:
Ceiling price = Warrant reference price + (ceiling price of underlying stock – reference price of underlying stock) x 1/Conversion ratio
Floor price = Warrant reference price – (reference price of the underlying stock – floor price of the underlying stock) x 1/Conversion ratio
In case the floor price of the warrant is less than or equal to zero (0), the floor price will be the smallest quoted unit equal to 10 VND.
– In case the ceiling price or floor price of stocks, closed-end fund certificates, or ETF fund certificates is determined to be equal to the reference price:
Adjusted ceiling price = Reference price + one quoted price unit
Adjusted floor price = Reference price – one quoted price unit
In case the floor price after adjusting in the above way is less than or equal to zero (0), the floor price will be adjusted to the reference price.
– For newly listed stocks, closed-end fund certificates, and ETF certificates, on the first trading day, the trading price will fluctuate within +/-20% of the expected trading price. Listing organizations and securities companies acting as listing consultants (if any) must provide the expected trading price to calculate the reference price for stocks, closed-end fund certificates, and ETF fund certificates on the first trading day. If within the first 3 trading days, newly listed stocks, closed-end fund certificates, or ETF certificates still do not have a closing price, the listed organization must have its reference price re-determined.
– For (buy) warrants, the reference price on the first trading day is determined as follows:
Reference price of warrant = Issuing price of warrant x (Reference price of underlying stock on the first trading day of the warrant/ Reference price of underlying stock on the date of announcement of warrant issuance) x (Conversion rate at the announcement date of warrant issuance /Conversion rate at the first trading day)
– For stocks, closed-end fund certificates, and ETF certificates that are traded again after suspending trading for more than 25 days, the price fluctuation range on the first trading day is +/-20% compared to the reference price. shown on the first day of resumption of trading.
– For warrants, the reference price on the first trading day after trading is suspended for more than 25 days is determined as follows:
Reference price = Closing price on the trading day immediately preceding the trading suspension date x (reference price of the underlying stock on the first trading day of CQ when trading resumes/ Reference price of the underlying stock at Trading day immediately preceding the date of suspension of trading) x (Conversion rate on the trading day immediately preceding the date of temporary suspension of trading on warrants / Conversion rate on the first trading day of the warrant after resuming trading )
– If in the first 3 days after resuming trading, stocks, closed-end fund certificates, and ETF certificates that are re-trading still do not have a closing price, HSX will consider adjusting the price fluctuation range of the stock. shares, closed-end fund certificates, ETF fund certificates after approval from SSC (State Security Commission of Vietnam)

1. ATO/ATC orders
– Is a trading order at the matching price that determines the opening price (Abbreviated as ATO) or closing price (Abbreviated as ATC).
– An order to buy or sell securities at the opening/closing price
– Orders are given priority before limit orders during order matching.
a. If there are only ATO/ATC orders on the order book:
ATO orders:
– Is the reference price if there are only orders to buy at ATO or sell at ATO or the total volume of orders on the buying side is equal to the selling side
– Is the price 1 quote unit higher than the reference price if the total volume of orders on the buying side is greater than the total volume of orders on the selling side.
– Is the price 1 quoted price unit lower than the reference price if the total volume of orders on the seller’s side is greater than the total volume of orders on the buyer’s side (if lower than the floor price, it is recorded as the floor price.
ATC orders:
– Is the latest exercise price or reference price (in case there is no latest execution price) if the order book only has ATC buy or sell orders, or the total order volume of the buyer is equal to the seller’s
– Is the price 1 quoted price unit higher than the previous most recent realized price if the total volume of the buyer is greater than the seller (if higher than the ceiling price, it is recorded as the ceiling price)
– Is the price 1 quoted price unit lower than the previous most recent realized price if the total volume of the seller is greater than the buyer’s (if lower than the floor price, it is recorded as the floor price)

b. If there is a limit order on the order book:
ATO orders:
– The price of the ATO buy order: is the highest price of the following three prices: the highest buying price plus 1 quoted price unit (if higher than the ceiling price, it is determined to be the – ceiling price), the highest selling price of the counterparty and Reference prices.
– The price of the ATO sell order: is the lowest price of the following three prices: the lowest selling price minus 1 quoted price unit (if lower than the floor price, it is determined as the floor price), the lowest buying price of the counterparty and Reference prices.
ATC orders:
The price of the ATC buy order: is the highest price of the following three prices: the highest buying price plus 1 quoted price unit (if higher than the ceiling price, it is determined as the ceiling price), the highest selling price of the counterparty, latest exercise price or reference price if there is no latest exercise price
Price of the ATC sell order: is the lowest price of the following three prices: lowest selling price minus 1 quoted price unit (if lower than the floor price, it is determined as the floor price), lowest buying price of the counterparty, latest exercise price or reference price if there is no latest exercise price.
ATO / ATC orders are entered into the trading system during the periodic order matching period to determine the opening/closing price and will be automatically canceled after the time of determining the opening/closing price if the order is not executed. implemented or not implemented at all.”

2. Limit order (LO)
– An order to buy or sell securities at a specified price or better. The order is valid from the time it is entered into the trading system until the end of the trading day or until the order is canceled.
– Odd-lot stocks, closed-end fund certificates, ETFs and warrants can only use limit order types when trading.
– Do not conduct odd lot transactions with newly listed securities or resume trading after being temporarily suspended or suspended from trading for 25 consecutive trading days or more until a closing price is established.”

3. Market order (Abbreviated as MP)
– Is an order to buy/sell securities at the lowest selling price/highest buying price available on the market. When entered into the trading system, the MP buy order will be executed immediately at the lowest selling price and the order Selling MP will be done immediately at the highest buying price available on the market. If the order volume of the MP order has not yet been fully executed, the MP order will be considered a buy order at the higher ask price or a sell order at the next lower buy price available on the market and continue to match. .
– If the placed volume of the MP order remains after trading according to the above principles and cannot continue to be matched, the MP order will be converted into a buy limit order at a price one quote unit higher than the price. previous last trade or limit order to sell at a price one quote unit lower than the previous last traded price.
In case the last executed price is the ceiling price for an MP buy order or the floor price for an MP sell order, the market order will be converted into a buy limit order at the ceiling price or a sell limit order at the floor price.
– MP orders are valid during the continuous order matching session
– MP orders will be automatically canceled if there is no corresponding limit order at the time of entering the order into the trading system.
– After a partial match of a foreign investor’s MP purchase order, the remaining portion will be automatically canceled if the stock runs out of room.

1. Cancel transaction order:
Cancellation of matched trading orders is only valid for unexecuted orders or the remaining portion of unexecuted orders.
2. During the open periodic order matching session: cancellation of LO and ATO orders is not allowed.
3. During the continuous order matching session: LO orders are allowed to be canceled during the trading period.
4. During the closing periodic order matching session: LO and ATC orders are not allowed to be canceled (including LO orders transferred from the continuous order matching session).
5. Cancel the put-through transaction order:
– Transaction orders that have been placed on the trading system cannot be canceled.
– During the transaction, in case the representative of the Securities Company enters an incorrect order, the order will only be canceled if approved by the Stock Exchange and Investors.

In case of warrant expiration:
If the investor holds the warrant to maturity, the warrant is automatically paid if it is in a profitable state.
Payment time: E + 5 (E: warrant expiration date)
Payment method: Cash
Method: Direct allocation to securities account.

1. During the order matching transaction period:
– The volume of purchases of stocks and closed-end fund certificates by foreign investors is deducted from the volume allowed to buy immediately after the purchase order is executed; The volume of shares and closed-end fund certificates sold by foreign investors is added to the volume of shares and closed-end fund certificates allowed to be purchased immediately after completing the transaction payment.
– An unfulfilled order or part of an order to buy shares or closed-end fund certificates of a foreign investor will be automatically canceled if the volume of shares or closed-end fund certificates allowed to be purchased is exhausted or is not executed immediately. when entering into the trading system.
2. During the put-through transaction period:
The volume of securities allowed to be purchased by foreign investors will not change if the transaction is negotiated between two foreign investors.