KEY POINTS
- SET will introduce eight enhanced trading measures, effective from November 16, 2026, following a market consultation and approval from the SEC.
The Stock Exchange of Thailand (SET) will implement eight revised trading measures from November 16, 2026, following a market consultation with investors and other stakeholders in May this year and approval from the Securities and Exchange Commission (SEC) Board.
SET President Asadej Kongsiri said that the measures aim to enhance market quality and fairness, curb abnormal price volatility and regulate inappropriate trading behavior, aligning regulations with the current investment context and international best practices to bolster confidence in the Thai capital market under the vision "The Trusted Gateway to Inclusive Opportunities."
“This suite of measures aim to balance market liquidity and stability, lower trading costs for all investor groups, and enforce supervision based on actual trading behavior, ensuring investors can be confident in the fairness of the Thai capital market,” said Asadej.
Key revisions:
- Narrower tick sizes for securities priced between THB 5-50 per share. This will narrow bid-ask spreads and improve the chances of order matching, lowering trading costs for all investor groups and improving market liquidity.
- Revised short-selling price rule. Under normal conditions, the Zero-Plus Tick rule will apply (short-sell orders must be at or above the last traded price). If a security’s closing price falls by 10 percent or more from the previous day’s close, the Uptick rule will apply on the next trading day (short-selling orders must be above the last traded price). This is intended to ease selling pressure during volatile periods without affecting liquidity or trading costs under normal conditions.
- Revised list of short-sell eligible securities, Eligibility is for highly liquid securities only: SET100 constituents, stocks underlying Single Stock Futures, depositary receipts (DRs) and exchange-traded funds (ETFs).
- Revised criteria for SET-registered accounts, based on the use of a dedicated order-submission channel (Dedicated API) or high-frequency trading (HFT) characteristics, such as order submission frequency or speed, end-of-day positions and daily trading value, to ensure appropriate supervision.
- Extra charge on accounts with a high order-to-trade ratio (High OTR). This applies to trading accounts that submit a large volume of orders but have a low number of matched trades. Accounts with an OTR above 50 times that also submit an average of over 50 orders per minute will incur an extra charge of THB 0.15 per order for orders exceeding 15,000 per day. The charge is intended to reflect the actual cost of order submission and deter orders placed without genuine trading intent.
- Removal of the Dynamic Price Band (DPB) to reduce barriers to trading, particularly triggering low-liquidity stocks.
- Removal of restrictions on securities eligible for HFT trading. This subjects all investor groups to the same supervisory framework, in line with international standards, while enhancing trading flexibility and ensuring equal across all security types.
- Removal of the Minimum Resting Time (MRT) to streamline order management and reduce the system operational burden on member trading systems.
For details of the revised rules, please visit www.set.or.th, under “Rules & Regulations” and "Rules – Circulars on Securities Trading,” in the document titled “Summary of Key Amendments to SET Rules on Trading Supervision Measures."
