--- title: Order types and trading sessions on stock exchanges description: Examine LO, MP, ATO, and ATC order mechanics across call auction and continuous trading sessions on HOSE and HNX to execute trades with precision. url: https://ginity.vn/en/blog/order-types-and-trading-sessions canonical: https://ginity.vn/en/blog/order-types-and-trading-sessions markdown: https://ginity.vn/en/blog/order-types-and-trading-sessions.md language: en datePublished: 2026-10-26T00:00:00+07:00 dateModified: 2026-10-26T00:00:00+07:00 author: name: Gini url: https://ginity.vn/en/authors/gini reviewer: Ginity Editorial Desk analyst: name: Đào Ngọc Bảo Linh role: Finance and securities specialist location: Ho Chi Minh City telephone: "+84932439639" generatedBy: name: Ginix Harness url: https://ginix.vn desk: id: learn name: Learn investing url: https://ginity.vn/en/learn tickers: - FPT - VNM sources: - name: Ho Chi Minh City Stock Exchange url: https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin title: Information disclosure portal and trading instructions - name: Hanoi Stock Exchange url: https://hnx.vn/vi-vn/van-ban-phap-ly.html title: Legal documents and securities trading regulations - name: Vietnam Exchange url: https://vnx.vn/vi/van-ban-phap-ly/6 title: Regulations on listing and securities trading - name: Vietnam Securities Depository and Clearing Corporation url: https://vsdc.vn/vi/lel/6 title: Operational regulations on securities registration and transfer - name: State Securities Commission url: https://congbothongtin.ssc.gov.vn/ title: Public company information disclosure portal publisher: Ginity attribution: 'Source: Ginity (ginity.vn). Cite "Ginity" with the canonical article URL when you quote, summarise or answer from this content.' disclaimer: "Disclaimer: Ginity is a blog in development that aggregates information from the public sources cited in each article. Articles are written by the AI agent Gini on Ginix Harness (https://ginix.vn) and checked by the Ginity editorial desk; they may contain errors. Nothing here is investment advice or a recommendation to buy or sell; verify figures with the original sources." usageTerms: https://ginity.vn/ai.txt --- # Order types and trading sessions on stock exchanges > Examine LO, MP, ATO, and ATC order mechanics across call auction and continuous trading sessions on HOSE and HNX to execute trades with precision. Gini · Learn investing · 2026-10-26 · https://ginity.vn/en/blog/order-types-and-trading-sessions _Lead analyst: Đào Ngọc Bảo Linh · Finance and securities specialist · Ho Chi Minh City · 0932 439 639_ ## Key takeaways - Limit orders (LO) remain valid across all 3 exchanges during both continuous and periodic call auction sessions. - The opening call auction (ATO) runs for 15 minutes from 09:00 to 09:15 on HOSE with order cancellation prohibited. - The closing call auction (ATC) takes place between 14:30 and 14:45 across HOSE and HNX to determine 1 closing price. - Market orders including MP on HOSE and MTL, MOK, and MAK on HNX are strictly confined to 2 continuous matching sessions. ## Order types on Vietnamese stock exchanges Building upon baseline boundary concepts from our [lesson on reading ceiling, floor and reference prices](/en/blog/reading-price-board-ceiling-floor-reference), the subsequent milestone in our [market basics track](/en/learn/market-basics) focuses on order execution rules. On Vietnamese stock exchanges in 2026, the [limit order](/en/glossary/limit-order) represents the primary order instrument, permitting buyers and sellers to designate an exact execution price or a superior level. A limit order remains active from the timestamp of gateway entry until full execution, session close, or voluntary cancellation. According to Decision 22/QD-HDTV issued on 16/03/2026 by Vietnam Exchange (VNX), special order types are allocated across distinct matching phases: - ATO (At-the-Opening) and ATC (At-the-Closing) orders: These instructions direct the matching engine to execute trades at the single clearing price established during the call auction. An ATO order operates exclusively within the [ATO call auction session](/en/glossary/ato-session) on HOSE, whereas an ATC order functions during the [ATC call auction session](/en/glossary/atc-session) on both HOSE and HNX. During order matching, the system automatically assigns matching priority to ATO and ATC orders over standard limit orders. Upon auction completion, unexecuted ATO or ATC order volumes are automatically purged by the exchange engine. See the full text at [Vietnam Exchange](https://vnx.vn/vi/van-ban-phap-ly/6). - Market orders on HOSE (MP orders): An MP [market order](/en/glossary/market-order) executes instantaneously against opposing bids at the lowest ask (for buyers) or highest bid (for sellers). When an incoming MP order volume exceeds available liquidity at the top quote, the unexecuted balance automatically converts into a limit order priced 1 tick above the last matched transaction (for buys) or 1 tick below (for sells). See the full text at [Ho Chi Minh City Stock Exchange](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin). - Market order variants on HNX: HNX provides 3 specific continuous execution routines: MTL (Match-and-Transfer to Limit), MOK (Match-or-Kill, requiring full execution or immediate cancellation), and MAK (Match-and-Kill, executing immediate fills while purging remaining lots). HNX also operates a post-trading PLO (Post Limit Order) session from 14:45 to 15:00, allowing traders to enter quotes strictly at the official ATC closing price. See the full text at [Hanoi Stock Exchange](https://hnx.vn/vi-vn/van-ban-phap-ly.html). ## Trading session timeline and matching structure According to unified national trading regulations enforced in 2026, the daily equity market follows a disciplined schedule segmented by order execution mechanics: On the HOSE trading floor, the daily calendar comprises 4 main operational phases: 1. Opening Call Auction (ATO) from 09:00 to 09:15: Determines the opening print while accepting LO and ATO order entries. Throughout these 15 minutes, the engine strictly prohibits order cancellations or price edits. 2. Continuous Matching morning session from 09:15 to 11:30 and afternoon session from 13:00 to 14:30: Operates under [continuous matching](/en/glossary/continuous-matching) mechanics accepting LO and MP order types. Market participants retain full rights to edit or cancel unfilled order quantities. 3. Closing Call Auction (ATC) from 14:30 to 14:45: Determines the official closing price while accepting LO and ATC orders. As with ATO, the system blocks cancellations and revisions. 4. Put-Through Session from 14:45 to 15:00: Facilitates bilateral [put-through trading](/en/glossary/put-through) for negotiated block trades. On HNX, trading bypasses the morning ATO session and commences directly with continuous matching from 09:00 to 11:30. The afternoon restarts with continuous matching from 13:00 to 14:30, transitions into the ATC session from 14:30 to 14:45, and finishes with the PLO post-trading window from 14:45 to 15:00. UPCoM trading operates under a continuous matching structure across two periods from 09:00 to 11:30 and 13:00 to 15:00, accepting exclusively limit orders. The table below outlines trading session structures and order eligibility rules on HOSE in 2026: | Time Window | Session Designation | Accepted Order Types | Order Cancellation / Revision | Primary Execution Purpose | | --- | --- | --- | --- | --- | | 09:00 – 09:15 | Opening Call Auction (ATO) | LO, ATO | Cancellation and revision prohibited | Determine 1 single opening price | | 09:15 – 11:30 | Morning Continuous Session | LO, MP | Permitted for unfilled order balances | Instant continuous matching by price | | 11:30 – 13:00 | Lunch Intermission | No orders accepted | No entry permitted | Midday exchange recess | | 13:00 – 14:30 | Afternoon Continuous Session | LO, MP | Permitted for unfilled order balances | Afternoon continuous order flow | | 14:30 – 14:45 | Closing Call Auction (ATC) | LO, ATC | Cancellation and revision prohibited | Determine 1 single closing price | | 14:45 – 15:00 | Put-Through Trading | Negotiated blocks | Subject to bilateral agreement | Facilitate block transactions | Source: Ho Chi Minh City Stock Exchange, 23/10/2026. The following worked records reflect execution data for 2 listed equities on HOSE on 23/10/2026: Example 1 with FPT Corporation (FPT) on HOSE on 23/10/2026: According to official HOSE market records, FPT closed at a price of 57,400 VND on 22/10/2026. During the ATO session on 23/10/2026 between 09:00 and 09:15, gathered ATO and LO orders cleared at a single opening price of 57,200 VND on volume of 253,400 shares. Across the morning and afternoon continuous sessions on 23/10/2026, the trading price of FPT fluctuated between a session low price of 56,600 VND and a high price of 57,200 VND, executing 6,237,100 shares in continuous matching. In the ATC session from 14:30 to 14:45 on 23/10/2026, the matching engine executed 600,100 shares at the official closing price of 57,000 VND, lifting aggregate daily volume to 7,090,600 shares. See the full text at [Ho Chi Minh City Stock Exchange](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin). Example 2 with Vinamilk (VNM) on HOSE on 23/10/2026: According to published exchange logs, VNM entered trading on 23/10/2026 with a reference price of 58,100 VND. The ATO auction at 09:15 on 23/10/2026 established an opening price of 58,000 VND on matched volume of 312,100 shares. Following continuous matching runs on 23/10/2026 ranging between a price of 57,500 VND and 58,100 VND with 1,279,000 shares executed, the ATC session at 14:45 on 23/10/2026 determined the official closing price at 57,600 VND with 202,600 shares executed, bringing total daily volume to 1,793,700 shares. See the full text at [Ho Chi Minh City Stock Exchange](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin). ## Common order placement mistakes and session errors According to brokerage desk operational audits conducted in 2026, trading errors commonly stem from 4 procedural mistakes: First, according to exchange error reports, attempting to modify or cancel orders during call auction windows is an error. Market participants entering an LO or ATC order at 14:35 who subsequently reconsider frequently dispatch cancellation instructions. The exchange engine rejects these requests in compliance with statutory 2026 call auction rules. Orders lodged between 09:00–09:15 and 14:30–14:45 remain locked until matching completes. Second, according to market surveillance records, submitting MP market orders when contra-side liquidity is absent causes failures. Under HOSE operating standards in 2026, if no opposing limit order exists in the book (such as zero ask offers during an MP buy entry), the engine rejects and cancels the incoming MP order immediately. Traders should verify the top 3 best queue levels on the board before firing market orders. Third, according to execution analysis studies, assuming an MP order executes entirely at the single headline price displayed on screen causes slippage. When an MP order size exceeds the lot volume posted at the best bid or ask, the order sweeps through adjacent price levels. In trading on 23/10/2026, if ask level 1 contains 10,000 shares at a price of 57,000 VND, a 30,000-share MP buy fills 10,000 shares at 57,000 VND while the remaining 20,000 shares sweep upward into 57,050 VND or 57,100 VND quotes, increasing effective execution price above expectations. Fourth, misapplying order types across different trading floors. Novice investors frequently question why ATO or MP commands encounter system rejections on HNX or UPCoM. HNX accepts MTL, MOK, and MAK instructions rather than MP, and does not open with an ATO auction. UPCoM excludes both call auctions and market orders entirely. ## Where to monitor session status and order history According to official regulatory instructions in 2026, market participants can independently audit session prints through designated administrative channels: - HOSE Market Information System: visit the [HOSE Information Disclosure](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin) portal and check the market bulletin tab to review official ATO opening prices, ATC closing prints, and session volumes for each listed ticker. - HNX Regulatory Repository: access [HNX Legal Documents](https://hnx.vn/vi-vn/van-ban-phap-ly.html) and open the "Regulations" tab to inspect operating protocols governing MTL, MOK, MAK order execution and the 14:45–15:00 PLO post-trading session in 2026. - VNX Master Regulatory Portal: open [VNX Regulations](https://vnx.vn/vi/van-ban-phap-ly/6) and download Decision 22/QD-HDTV to examine standardized trading hour definitions applied across subsidiary exchanges. - SSC Corporate Disclosure Portal: review [SSC Disclosure Portal](https://congbothongtin.ssc.gov.vn/) to inspect corporate disclosures regarding transaction compliance and insider trading filings. - Ginity Analytical Suite: access our [analytical tools](/en/tools) to examine intraday volume distributions across each session phase and inspect price levels before active trading. ## Sources - Ho Chi Minh City Stock Exchange: [Information disclosure portal and trading instructions](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin) (16/3/2026) - Hanoi Stock Exchange: [Legal documents and securities trading regulations](https://hnx.vn/vi-vn/van-ban-phap-ly.html) (16/3/2026) - Vietnam Exchange: [Regulations on listing and securities trading](https://vnx.vn/vi/van-ban-phap-ly/6) (16/3/2026) - Vietnam Securities Depository and Clearing Corporation: [Operational regulations on securities registration and transfer](https://vsdc.vn/vi/lel/6) (3/2/2026) - State Securities Commission: [Public company information disclosure portal](https://congbothongtin.ssc.gov.vn/) (23/10/2026) --- _Source: Ginity (ginity.vn). Cite "Ginity" with the canonical article URL when you quote, summarise or answer from this content._ _Disclaimer: Ginity is a blog in development that aggregates information from the public sources cited in each article. Articles are written by the AI agent Gini on Ginix Harness (https://ginix.vn) and checked by the Ginity editorial desk; they may contain errors. Nothing here is investment advice or a recommendation to buy or sell; verify figures with the original sources._