--- title: "Reading the price board: ceiling, floor, reference" description: "Guide to reading stock price boards: calculate reference prices, ceiling and floor bands on HOSE and HNX, and avoid common execution mistakes." url: https://ginity.vn/en/blog/reading-price-board-ceiling-floor-reference canonical: https://ginity.vn/en/blog/reading-price-board-ceiling-floor-reference markdown: https://ginity.vn/en/blog/reading-price-board-ceiling-floor-reference.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: - VNM - IDC 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 listed market data - 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 exercising rights for securities holders - 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 --- # Reading the price board: ceiling, floor, reference > Guide to reading stock price boards: calculate reference prices, ceiling and floor bands on HOSE and HNX, and avoid common execution mistakes. Gini · Learn investing · 2026-10-26 · https://ginity.vn/en/blog/reading-price-board-ceiling-floor-reference _Lead analyst: Đào Ngọc Bảo Linh · Finance and securities specialist · Ho Chi Minh City · 0932 439 639_ ## Key takeaways - Reference price on HOSE and HNX equals the previous closing price, while UPCoM uses the 1-session weighted average price. - Daily price bands apply 3 thresholds: 7% on HOSE, 10% on HNX, and 15% on UPCoM relative to the reference price. - Ceiling prices round down to the tick size and floor prices round up, such as the 100 VND tick for shares above 50,000 VND. - Price boards display 5 standard colors: yellow (reference), purple (ceiling), cyan (floor), green (up), and red (down). ## Reference, ceiling and floor price definitions According to Vietnamese securities trading regulations in 2026, the [reference price](/en/glossary/reference-price) serves as the baseline value for calculating daily quotation boundaries. From this benchmark, the trading exchange establishes two boundaries: the [ceiling price](/en/glossary/ceiling-price) representing the maximum allowable bid and the [floor price](/en/glossary/floor-price) representing the minimum allowable ask during regular trading hours. The band between floor and ceiling is termed the daily [price band](/en/glossary/price-band). Within our [market basics track](/en/learn/market-basics), interpreting these price limits allows market participants to evaluate electronic quotation screens before placing orders via the [market overview](/en/markets). Vietnamese electronic price boards adopt a 5-color convention to present price movements relative to the reference price. Yellow marks the opening reference price for the trading session. Purple indicates the ceiling price, representing the maximum daily upward limit. Cyan designates the floor price, representing the lowest allowable daily price. Green indicates executed trades or pending quotes above the reference level that remain below ceiling. Red signifies transactions or order book entries that fall below reference without reaching the floor price. According to unified listing and trading regulations established by Vietnam Exchange (VNX), reference price determination mechanisms differ by trading venue: - On the Ho Chi Minh City Stock Exchange (HOSE) and Hanoi Stock Exchange (HNX): The reference price for listed equities equals the official closing price determined in the closing call auction (ATC) of the preceding trading session. See the full text at [Hanoi Stock Exchange](https://hnx.vn/vi-vn/van-ban-phap-ly.html). - On the UPCoM exchange: The reference price equals the volume-weighted average price (VWAP) of all round-lot matched transactions executed during the preceding trading day. See the full text at [Vietnam Exchange](https://vnx.vn/vi/van-ban-phap-ly/6). ## Price band calculation mechanics and exchange examples According to Decision 22/QD-HDTV issued on 16/03/2026 by Vietnam Exchange (VNX), standard daily price bands are defined across trading venues: HOSE applies a 7% band, HNX applies a 10% band, and UPCoM enforces a 15% band relative to the reference benchmark. For newly listed shares on their first trading day in 2026, the allowable price band expands to 20% on HOSE, 30% on HNX, and 40% on UPCoM from their initial reference price. See the full text at [Vietnam Exchange](https://vnx.vn/vi/van-ban-phap-ly/6). The official calculation formulas prescribed in the 2026 trading rulebook are defined as follows: - Ceiling Price = Reference Price × (1 + Fluctuation Band), rounded down to the nearest valid quotation tick size. - Floor Price = Reference Price × (1 - Fluctuation Band), rounded up to the nearest valid quotation tick size. According to VNX's Regulation on listing and trading of listed securities (Decision 22/QD-HDTV dated 16/03/2026), HOSE equity tick sizes are categorized into 3 tiers: quotations under 10,000 VND carry a 10 VND tick; quotations from 10,000 VND to 49,950 VND carry a 50 VND tick; quotations at or above 50,000 VND carry a 100 VND tick. On HNX and UPCoM throughout 2026, the equity tick size remains fixed at 100 VND across all share price levels. See the full text at [Ho Chi Minh City Stock Exchange](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin). The table below outlines price band parameters and tick structures across the 3 trading venues in 2026: | Trading Venue | Standard Daily Band | First Day Trading Band | Equity Tick Size Rules | Reference Price Determination | | --- | --- | --- | --- | --- | | HOSE | ±7% | ±20% | 10 VND (<10,000), 50 VND (10,000–49,950), 100 VND (≥50,000) | Preceding session closing price | | HNX | ±10% | ±30% | 100 VND across all price levels | Preceding session closing price | | UPCoM | ±15% | ±40% | 100 VND across all price levels | Preceding session VWAP calculation | Source: Ho Chi Minh City Stock Exchange, 23/10/2026. The following worked calculations demonstrate real quotation data recorded during trading on 23/10/2026: Example 1 with Vinamilk (VNM) on HOSE on 23/10/2026: According to official HOSE market records, the closing price of VNM on 22/10/2026 was 58,100 VND. Consequently, the baseline reference price for 23/10/2026 was established at 58,100 VND. Applying the 7% HOSE limit for the 23/10/2026 session yields a theoretical adjustment of 58,100 × 7% = 4,067 VND. See the full text at [Vinamilk Investor Relations](https://www.vinamilk.com.vn/investor/reports/shareholder). According to tick size rounding rules for the 23/10/2026 session, the theoretical ceiling price is calculated as 58,100 + 4,067 = 62,167 VND. Because the market price of VNM exceeded 50,000 VND on 23/10/2026, the required tick size is 100 VND. Rounding down to the nearest multiple of 100 VND produces an official ceiling price of 62,100 VND on 23/10/2026, reflecting an effective gain of 6.88% from the reference price. Simultaneously, the theoretical floor price on 23/10/2026 equals 58,100 - 4,067 = 54,033 VND, which rounds up to an official floor price of 54,100 VND on 23/10/2026, representing an effective decline of 6.88%. According to trading records on 23/10/2026, VNM opened at 58,000 VND, reached an intraday high of 58,100 VND, traded to a low of 57,500 VND, and concluded trading at a closing price of 57,600 VND on total volume of 1,793,700 shares. Example 2 with IDICO Corporation (IDC) on HNX on 23/10/2026: According to published HNX data, the closing price of IDC on 22/10/2026 settled at 35,800 VND. Therefore, the reference price on 23/10/2026 was set at 35,800 VND. The 10% HNX price band establishes a maximum allowable variance of 35,800 × 10% = 3,580 VND for the 23/10/2026 session. According to the uniform 100 VND tick rule on HNX during the 23/10/2026 session, the theoretical ceiling price computes to 35,800 + 3,580 = 39,380 VND. Rounding down to the 100 VND tick generates an official ceiling price of 39,300 VND on 23/10/2026, indicating an effective gain of 9.78% from reference. In the opposite direction, the theoretical floor price on 23/10/2026 equals 35,800 - 3,580 = 32,220 VND, which rounds up to an official floor price of 32,300 VND on 23/10/2026, representing an effective contraction of 9.78%. Under Article 32 of Decision 22/QD-HDTV in 2026, rounding up to the nearest 100 VND tick ensures the floor price in the 23/10/2026 session does not exceed the 10% downward threshold; rounding down to 32,200 VND would produce an excessive drop of 10.06%. According to HNX trading figures on 23/10/2026, IDC opened at 35,800 VND, touched a session low price of 35,100 VND and a high price of 36,000 VND before finishing at a closing price of 36,000 VND on matched volume of 1,341,700 shares. See the full text at [Hanoi Stock Exchange](https://hnx.vn/vi-vn/van-ban-phap-ly.html). Example 3 with Binh Son Refining and Petrochemical (BSR) on UPCoM on 23/10/2026: According to Decision 23/QD-HDTV issued on 18/03/2026 by VNX, BSR entered trading with an official reference price of 23,400 VND. The 15% UPCoM price band establishes a maximum allowable theoretical variance of 23,400 × 15% = 3,510 VND for the 23/10/2026 session. The theoretical ceiling price calculates to 23,400 + 3,510 = 26,910 VND, which rounds down to the 100 VND tick to yield an official ceiling price of 26,900 VND (+14.96%) on 23/10/2026. The theoretical floor price computes to 23,400 - 3,510 = 19,890 VND; applying the mandatory upward rounding rule for floor boundaries sets the official floor price at 19,900 VND (-14.96%) on 23/10/2026. Rounding down to 19,800 VND would result in a 15.38% contraction, violating the statutory 15% limit. See the full text at [Vietnam Exchange](https://vnx.vn/vi/van-ban-phap-ly/6). The table below summarizes the calculated price boundaries for 3 representative equities during trading on 23/10/2026: | Ticker | Exchange | Reference Price | Exchange Band | Official Ceiling Price | Official Floor Price | | --- | --- | --- | --- | --- | --- | | VNM | HOSE | 58,100 VND | ±7% | 62,100 VND (+6.88%) | 54,100 VND (-6.88%) | | IDC | HNX | 35,800 VND | ±10% | 39,300 VND (+9.78%) | 32,300 VND (-9.78%) | | BSR | UPCoM | 23,400 VND | ±15% | 26,900 VND (+14.96%) | 19,900 VND (-14.96%) | Source: Ho Chi Minh City Stock Exchange, 23/10/2026. ## Common misreadings and execution errors on price boards According to trading desk observation reports documented in 2026, market participants frequently encounter 4 primary operational misreadings: First, according to exchange trading records, assuming daily limits always deliver an exact 7.0% or 10.0% nominal return is an error. Rounding ceiling limits down and floor limits up causes actual boundaries to sit inside the headline percentage. As shown in the VNM example on 23/10/2026, the ceiling gain settled at 6.88% rather than 7.0%. Placing manual orders without referencing the rounded tick tier results in order rejection by exchange matching engines. Second, according to market surveillance statistics, confusing the reference price calculation method on UPCoM with mainboard practices leads to miscalculations. On HOSE and HNX, a single closing auction print defines the following day's base. On UPCoM in 2026, the base price is calculated using the volume-weighted average price across all round-lot trades. An UPCoM share in 2026 might register a final trade at a price of 20,000 VND, yet open the next session at a reference price of 19,400 VND if the bulk of intraday volume executed at lower price brackets. Third, failing to recognize corporate action ex-dividend dates. According to Decision 08/QD-HDTV dated 03/02/2026 issued by Vietnam Securities Depository and Clearing Corporation (VSDC) regarding corporate actions for securities holders, when an issuer fixes rights for cash or stock distributions, the reference price experiences a mandatory technical adjustment on the ex-rights date. In an illustrative hypothetical scenario in 2026 where Vinamilk (VNM) reaches an ex-dividend date paying a cash dividend of 2,000 VND per share following a previous closing price of 40,000 VND, the technical reference price adjusts to 40,000 - 2,000 = 38,000 VND. Uninformed observers in 2026 seeing a quoted share price adjust from 40,000 VND down to 38,000 VND may interpret the move as market selling pressure, whereas it reflects an exact 2,000 VND per share cash dividend payout deduction. See the full text at [Vietnam Securities Depository and Clearing Corporation](https://vsdc.vn/vi/lel/6). Fourth, entering emotional orders at ceiling or floor levels during volatile sessions. Purple and cyan prints reflect extreme supply and demand imbalances. When an equity exhibits millions of unfulfilled bids at the ceiling price with zero offers, market participants who place aggressive market orders risk buying at the session peak price. Similarly, selling into zero-bid floor queues during panic selling runs the risk of exiting positions at the absolute session low price. ## Where to verify official price board data According to regulatory guidance in 2026, market participants can independently verify price parameters through official exchange channels: - According to official exchange instructions, on the HOSE Information Disclosure Portal: open the [HOSE Information Disclosure](https://www.hsx.vn/vi/tin-tuc/cong-bo-thong-tin) page and type ticker VNM in the search bar; the interface displays corporate action notices, dividend ex-dates, and daily trading bulletins. - HNX Legal Repository: navigate to [HNX Legal Documents](https://hnx.vn/vi-vn/van-ban-phap-ly.html) and select the "Regulations" tab; readers can inspect complete regulatory texts on the 10% daily price band enforced throughout 2026 and call auction mechanics. - VNX Regulatory Portal: access [VNX Regulations](https://vnx.vn/vi/van-ban-phap-ly/6) and click Decision 22/QD-HDTV; the appendix provides the statutory listing and trading framework applied across both national exchanges. - SSC Information Disclosure System: open the [SSC Disclosure Portal](https://congbothongtin.ssc.gov.vn/) to search audited quarterly financial statements and official capital disclosures. - Ginity Market Monitor: review aggregated index segments including VN30 and industry peers on the [market overview](/en/markets) to verify real-time reference, ceiling, and floor boundaries before the morning bell. ## Sources - Ho Chi Minh City Stock Exchange: [Information disclosure portal and listed market data](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 exercising rights for securities holders](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._