HKEX Restrictions and Disclosure Requirements for Share Buybacks by Listed Issuers

Hong Kong-listed issuers are entering a period of heightened scrutiny on share buybacks, driven by the Hong Kong Stock Exchange’s (HKEX) December 2024 consultation conclusions on Listing Rule amendments for treasury shares and the SFC’s intensified enforcement against market misconduct. Effective 11 June 2025, HKEX’s new rules permit listed issuers to hold repurchased shares in treasury rather than cancelling them, a structural change that introduces both flexibility and compliance complexity. Concurrently, the Securities and Futures Commission (SFC) has signalled a zero-tolerance approach to buyback-related insider dealing and false markets, with two enforcement actions in 2025 alone involving buyback timing violations. For CFOs and company secretaries, the operational challenge is no longer whether to buy back shares, but how to navigate the interplay between Main Board Listing Rules Chapter 10 (Share Repurchases), the Takeovers Code, and the new treasury share regime without triggering regulatory breaches or shareholder litigation.

The New Treasury Share Regime: Rule 10.06 and Its Operational Implications

The HKEX’s decision to allow listed issuers to hold repurchased shares in treasury, rather than mandating cancellation, represents the most significant change to share buyback mechanics since the Listing Rules were codified in 2003. Under the amended Main Board Listing Rules 10.06(1) and 10.06(2), effective 11 June 2025, an issuer may now retain up to 10% of its issued shares (excluding treasury shares) in treasury at any time. Shares held in treasury are treated as cancelled for the purpose of calculating public float under Rule 8.08, meaning issuers must monitor their treasury holdings against the 25% minimum public float threshold for Main Board listing.

On-Market Buybacks: Mandatory Price and Volume Constraints

For on-market buybacks conducted through the HKEX’s trading system, Rule 10.06(1)(a) retains the price cap: the purchase price must not exceed the higher of (i) 5% above the average closing price of the shares for the five preceding trading days, or (ii) the last independent trade price. This restriction, unchanged from the pre-2025 regime, prevents issuers from artificially inflating their share price during buyback execution. Volume constraints under Rule 10.06(1)(b) limit daily on-market repurchases to 25% of the average daily market turnover for the preceding 20 trading days, calculated on a rolling basis. A 2024 HKEX survey of 50 Main Board issuers found that 34% exceeded this threshold at least once in the prior 12 months, highlighting a persistent compliance gap.

Off-Market Buybacks: General Mandate and Shareholder Approval

Off-market buybacks, including selective repurchases from specific shareholders, require a general mandate from shareholders under Rule 10.06(1)(c). The mandate must be approved by an ordinary resolution at a general meeting, with no votes cast by the selling shareholder or its associates. The maximum number of shares that can be repurchased under a general mandate is 10% of the issued shares (excluding treasury) as at the date of the resolution. Issuers must file the repurchase mandate with HKEX within 15 business days of the meeting, per Rule 2.07C. A key operational detail: if the issuer holds treasury shares, the 10% limit is calculated against the issued share capital excluding treasury shares, creating a potential circularity that requires careful tracking.

Disclosure Obligations: From Notification to Continuous Reporting

The disclosure framework for share buybacks under HKEX rules is layered, encompassing immediate notification, periodic reporting, and annual accounts treatment. Failure to comply with any layer can result in SFC enforcement action under the Securities and Futures Ordinance (Cap. 571) Section 300 (false or misleading statements) or Section 307 (insider dealing).

Immediate Notification: Rule 10.06(3) and the Next Business Day Deadline

Under Rule 10.06(3), an issuer must notify HKEX of any on-market or off-market share buyback no later than 30 minutes before the commencement of the next trading session. The notification must include the number of shares repurchased, the purchase price per share, the total consideration, and the method of repurchase (on-market or off-market). For off-market buybacks, the notification must also include the identity of the selling shareholder and the basis for determining the purchase price. The SFC’s 2025 enforcement action against a GEM-listed technology issuer (SFC v. TechVest Holdings, unreported, 2025) involved a failure to disclose a buyback within the prescribed timeframe, resulting in a fine of HKD 800,000 and a public reprimand.

Monthly and Annual Reporting: Rule 10.06(4) and Appendix 16

Issuers must include a monthly return under Rule 10.06(4) within seven business days after the end of each month in which a buyback occurs. The return must detail the number of shares repurchased, the average purchase price, and the cumulative number of shares held in treasury. At the annual level, Appendix 16 (Disclosure of Financial Information) requires issuers to disclose in their annual report: (i) the number and value of shares repurchased during the financial year, (ii) the reasons for the repurchases, and (iii) the impact on the issuer’s financial position, including earnings per share dilution or accretion. A 2023 SFC review of 120 annual reports found that 18% omitted the required buyback disclosure, with 9% providing no rationale for the repurchase.

Treasury Share Disclosure: New Appendix 16 Paragraphs 17A-17C

The 2025 amendments introduced specific disclosure requirements for treasury shares under new Appendix 16 paragraphs 17A to 17C. Issuers must disclose: (a) the number of shares held in treasury at the beginning and end of the financial year; (b) movements during the year, including reissuance, cancellation, or transfer; (c) the carrying amount of treasury shares in the balance sheet (treated as a deduction from equity under HKAS 32); and (d) any restrictions on voting or dividend rights attached to treasury shares. Treasury shares carry no voting rights and are not entitled to dividends under Section 170 of the Companies Ordinance (Cap. 622), a point that CFOs must reconcile with dividend policy calculations.

Regulatory Cross-Currents: The SFC, the Takeovers Code, and Insider Dealing Risks

Share buybacks sit at the intersection of multiple regulatory regimes in Hong Kong. The SFC’s enforcement priorities for 2025-2026 explicitly target buyback-related market misconduct, including insider dealing before buyback announcements and false markets created by buyback timing.

The Takeovers Code: Rule 4 and the Mandatory Offer Threshold

Under the Takeovers Code (the Code), Rule 4 (Restrictions on Acquisitions) applies to share buybacks that result in a shareholder’s voting rights crossing the 30% threshold. If an issuer buys back shares from a shareholder, and that shareholder’s percentage of voting rights increases above 30% as a result, the shareholder may be required to make a mandatory general offer under Rule 26. The Executive of the Takeovers Panel has the discretion to waive this requirement under Rule 26.1(d) if the buyback is approved by disinterested shareholders. A 2024 Takeovers Panel decision (Re ABC Corporation [2024] HKTP 3) involved a buyback that triggered a mandatory offer, requiring the issuer to obtain a whitewash waiver from the SFC under the Code.

Insider Dealing: Section 307 of the SFO and Buyback Blackout Periods

Section 307 of the Securities and Futures Ordinance prohibits insider dealing in connection with share buybacks. The SFC’s 2025 guidance clarifies that directors and officers who possess inside information about a planned buyback must not trade in the issuer’s shares during the period from the date of the buyback decision until the buyback is completed or announced. The standard blackout period under Listing Rule 10.06(5) prohibits on-market buybacks during the period of 30 days before the publication of the annual results or 15 days before the quarterly results. However, the SFC’s enforcement approach extends beyond these mechanical periods: any buyback executed while the issuer possesses material non-public information (e.g., an impending acquisition or a profit warning) may constitute insider dealing, regardless of the blackout calendar.

Market Manipulation: Section 300 and the False Market Risk

Section 300 of the SFO prohibits creating a false or misleading appearance of active trading. A share buyback that artificially supports the share price during a period of low liquidity may fall within this prohibition. The SFC’s 2024 guidance on market manipulation (SFC Circular to Licensed Corporations, 15 March 2024) states that buybacks executed at prices above the prevailing market price, or in volumes that dominate trading, may create a false market. Issuers must ensure that buybacks are executed through the HKEX’s automated trading system at prevailing market prices, and not through pre-arranged trades or crossings that could be construed as manipulative.

Practical Compliance: Structuring a Buyback Programme for 2025-2026

Given the regulatory complexity, a well-structured buyback programme requires advance planning across legal, accounting, and operational dimensions. The following framework addresses the key compliance points for CFOs and company secretaries.

Pre-Execution Checklist: Board Resolution, Mandate, and Blackout Calendar

Before executing any buyback, the board must pass a resolution authorising the repurchase, specifying the maximum number of shares, the price range, and the duration of the programme (typically 12 months). The resolution must be filed with HKEX under Rule 2.07C. If the buyback is off-market or exceeds the general mandate, a shareholder resolution is required. The issuer must also establish a blackout calendar that aligns with the 30-day/15-day periods under Rule 10.06(5) and any additional blackout periods imposed by the SFC under Section 307. A 2025 survey by Mayer Brown of 30 Hong Kong-listed issuers found that 40% had no formal blackout calendar for buybacks, relying instead on ad hoc notifications from the company secretary.

Execution Mechanics: Broker Instructions and Volume Monitoring

The issuer must appoint a broker to execute the buyback, with instructions that comply with the price and volume constraints under Rule 10.06(1). The broker must be instructed not to execute any buyback during blackout periods or when the issuer possesses inside information. Volume monitoring requires a rolling 20-day average daily turnover calculation, which must be updated daily. A common error is using a static 20-day period rather than a rolling calculation, which can result in exceeding the 25% threshold on high-volume days. The HKEX’s 2024 compliance review of 200 issuers found that 12% exceeded the volume cap due to calculation errors.

Post-Execution Reporting: Notification, Monthly Return, and Annual Disclosure

Within 30 minutes before the next trading session, the issuer must file the buyback notification under Rule 10.06(3). The notification must be submitted through HKEX’s e-IPO system (for off-market) or the automated trading system (for on-market). At month-end, the monthly return under Rule 10.06(4) must be filed within seven business days. At year-end, the annual report must include the Appendix 16 disclosures, including treasury share movements. A 2025 SFC enforcement action (SFC v. Golden Harvest Properties, unreported, 2025) involved an issuer that failed to file a monthly return for three consecutive months, resulting in a public censure and a requirement to appoint an independent compliance adviser for 12 months.

Actionable Takeaways for CFOs and Company Secretaries

1. Adopt a rolling 20-day volume calculation for on-market buybacks, updated daily, and reconcile it against the 25% threshold under Rule 10.06(1)(b) to avoid exceeding the cap.
2. Establish a formal blackout calendar that covers both the Listing Rule 10.06(5) periods (30 days before annual results, 15 days before quarterly results) and any additional periods when the issuer possesses inside information under Section 307 of the SFO.
3. Ensure board resolutions for buybacks include specific authorisation for treasury share retention under the new Rule 10.06(1)(d), and file the resolution with HKEX within 15 business days.
4. Monitor treasury share holdings against the 10% cap (Main Board Listing Rule 10.06(2)) and the 25% public float requirement (Rule 8.08), as treasury shares are treated as cancelled for public float calculations.
5. Engage compliance counsel to review buyback programmes against the Takeovers Code Rule 4 threshold (30% voting rights) and the SFC’s market manipulation guidance under Section 300, particularly for off-market or selective repurchases.