HNX Trading Regulations

Trading methods   Trading hours
Continuous Order Matching session I                  09:00 – 11:30
Continuous Order Matching session II       13:00 – 14:30
Periodical Order Matching – At the close   14:30 – 14:45
Post-session Order Matching                         14:45 – 15:00
Put-through Order Matching                      09:00 – 15:00
Continuous Order Matching session I       09:00 – 11:30
Continuous Order Matching session II 13:00 – 14:30
Periodical Order Matching – At the close 14:30 – 14:45
Put-through Order Matching 09:00 – 15:00
  • For stocks: ± 10% of the reference price
  • For stocks and ETFs which are newly listed or re-traded after more than 25 days of suspension: ± 30% of the reference price
  • For paying dividends/ treasury stocks bonus to exist shareholders on the ex-dividend date: ± 30% of the reference price
  • For Bonds: no regulation
  • Ceiling/floor price of Stocks and ETFs
    • Ceiling Price = Reference price + (Reference price x Ceiling price range)
    • Floor price = Reference price – (Reference price x Floor price range)
  • In case ceiling/floor price is equal to the reference price, the limitation of the price range is redefined as follows
    • Adjusted ceiling price = Reference price + 01 tick size
    • Adjusted floor price = Reference price – 01 tick size
  • When the reference price is 100 VND, the limitation of the price range is redefined as follows:
    • Adjusted ceiling price = Reference price + 01 tick size
    • Adjusted floor price = Reference price
  • Continuous Order Matching 
  • Periodical Order Matching
  • Put-through Order Matching
  • Price priority: Buy orders with higher prices or sell orders with lower prices will be prioritized to execute.
  • Time priority: 
    • In case multiple buy or sell orders have the same price, the order that first entered into trading system takes precedence.
    • In the Continuous order matching sessions, if the buy and sell orders meet the price conditions (Buy price ≥ Sell price), matched price shall be the price of the order entered into the system first.
  • For board-lots: 100 shares/ ETFs
  • Even-lot matching trading unit of corporate bonds: 01 bond
  • Volume of put-through transactions: From 5,000 shares or ETFs. No quotation unit for put-through transactions.
  • Trading unit, minimum trading volume for bond put-through transactions: 01 bond
  • Trading unit for odd-lot transactions: 01 share, ETFs. Odd-lot securities trading from 01 to 99 stocks, ETFs are executed by either continuous order matching or put-through matching method.
  • Put-through and odd-lot transactions are not allowed to execute on the first trading day of newly listed stocks or the re-traded day after 25 days of suspension until the closing price is determined.
  • Order matchings of stocks: VND 100
  • Order matchings of bonds: VND 01
  • Order matchings of ETFs: VND 01
  • Put-through orders of stocks and bonds: VND 01
  • The reference price is determined by the closing price of the previous trading day (which is the last matching price on the nearest previous trading day)
  • The prices of newly listed stocks and ETFs on the first trading day are defined as follows:
    • Predetermined reference price of a share on the first trade date is proposed by issuing organization or at the advice of a consulting organization (if any) and approved by HNX. 
    • In case the reference price is not determined in the first three trading days, the issuing organization and consulting organization (if any) shall redefine the reference price thereof.
  • For stocks that have been suspended for more than 25 consecutive trading days, the reference price on the first day of resume trading is determined by HNX and approved by State Securities Commission.
  • For stocks and ETFs trading are not entitled to dividends and attached rights, the reference price at the ex-dividend date is determined on the principle of taking the closing price of the most recent trading day adjusted according to the value of the dividend received or the value of attached rights.
  • Reference price is not adjusted in case the issuing organization issue convertible bond or issue additional shares (secondary equity offering) at higher price than the weighted price of shares traded on the previous trading day of the ex-rights day.

1. Stocks and ETFs trading

  • The Limit Order (LO) is valid from the time it is entered into the trading registration system until being canceled or end of trading sessions.
  • The Market Order (MP) is only entered into the system in the continuous order matching sessions:
    • Market to Limit (MTL) order is the order that can be executed totally or partially, the remaining part of MTL orders will be re-submitted into limit orders (LO)
    • Market - fill or kill (MOK) order is an order to buy or sell a security that must be executed immediately in its entirety; otherwise, the entire order is canceled; no partial fulfillments are allowed.
    • Market - Fill and Kill (MAK) is an order to buy or sell that can be filled partially or canceled. The remainder of the order is canceled immediately after the order is filled.
  • ATC orders are only valid during the Closing Periodic Order Matching:
    • This order is used to buy or sell securities at the closing price. ATC orders take priority over limit orders (LO) during order matching.
    • The Periodic Order Matching session, which determines the closing price, will not determine the matching price if there are only ATC orders on the order books.
    • ATC orders will automatically cancel themselves after the session expires if they are not executed or not totally executed.
  • Post Limit Order (PLO):
    • PLO are buying or selling orders at the closing price after the Closing Periodic Order Matching session expires.
    • Only entered into the trading system during the after-hours trading session.
    • Matched as soon as they enter the trading system if there are pending reciprocal orders. The execution price is the closing price of that trading day.
    • Not allowed to modify or cancel.
    • PLO will not be entered the system if the Continuous Order Matching and Closing Periodic Order Matching sessions do not determine the execution price, 

2. Bond trading

  • Only LO is applied.
  • Price or volume modification and order cancellation are only valid for the original unexecuted orders or the rest of the unexecuted orders.
  • In the Continuous Order Matching session: Limit Orders are allowed to modify price, volume, and cancel during the trading time. The order priority after being corrected is defined as follows:
    • The order priority remains unchanged if only the volume is amended to decrease.
    • The order priority is calculated from the time the correction orders are entered into the trading system for the case of amending to increase volume and/ or price correction.
  • In the Closing Periodic Marching session to determine the closing price (ATC): it is not allowed to modify or cancel LO and ATC orders (including LO orders transferred from the Continuous Order Matching sessions.
  • PLO is not allowed to be amended or canceled.
  • Buy or sell transactions of treasury stocks and market-making transactions of market makers must comply with specific regulations in Circular 203/2015/TT-BTC of the Ministry of Finance.
  • Transactions of major shareholders, internal shareholders and related persons must comply with specific regulations in the Law on Securities and Circular 96/2020/TT-BTC of the Ministry of Finance.