Lock-up: when pre-IPO shareholders can sell
A lock-up restricts existing shareholders, and often the company itself, from selling or issuing shares for a period after listing. It comes from two sources. Some exchanges impose it by rule. Elsewhere it is a contractual commitment to the underwriting banks, recorded in the underwriting agreement and disclosed in the prospectus. Market practice lock-ups are often longer or broader than the legal minimum, and early release normally requires the consent of the global coordinators.
| Exchange | Rule-based lock-up | Source |
|---|---|---|
| DFM, ADX | No mandatory lock-up in the listing rules; contractual in practice | DFM and ADX listing rules |
| Nasdaq Dubai Growth Market | 12 months for all pre-listing shareholders | DFSA MKT Rule 9.3.11 |
| Saudi Exchange Main Market | 6 months for substantial shareholders named in the prospectus | CMA OSCOs Art. 72 |
| Nomu | 12 months for substantial shareholders | Nomu rules |
| HKEX Main Board | Controlling shareholders: 6 months, then 6 months without losing control | HKEX Rule 10.07 |
| SGX Mainboard and Catalist | Promoters: 6 months, with at least 50% held for a further 6 months on some tests | SGX Rules 229 and 422 |
| AIM | 12 months for related parties if the business lacks a 2-year independent revenue history | AIM Rule 7 |
| LSE Main Market | None in the rules; 180-365 days common in practice | UK Listing Rules |
| Nasdaq, NYSE | None in the rules; 180 days common in practice | Exchange guides |
| Bahrain Bourse | Main Board founders 1 year; BIM founders 2 years, holding at least 30% | BHB rules |
Other markets have their own versions. Borsa Istanbul rules, as reported by secondary sources, prevent controlling shareholders and holders of 10% or more from selling on the exchange below the IPO price for one year. QSE requires founders of a transformed company to stay locked up for one year from first trading and to keep 40% jointly until the end of the second year. The expiry of a lock-up is a known date, and the market prices in the possibility of selling around it, so the company's IR team should prepare for it.
Continuous disclosure and inside information
A listed company must announce inside information promptly through the exchange's disclosure system. Inside information is precise information, not yet public, that would be likely to have a significant effect on the share price if it were made public: a major contract, a profit warning, a change of control, litigation, a regulatory action. Delay is allowed only under narrow conditions and must be documented. Selective disclosure, telling some investors before others, is prohibited.
- An insider list records everyone with access to inside information on a given matter.
- Directors and senior managers are subject to closed periods before results and must report their own dealings.
- A disclosure committee or a clear procedure decides what is announced, when and by whom.
- Rumours and leaks may trigger an obligation to announce earlier than planned.
Periodic reporting
The calendar of reports becomes fixed. Frequency depends on the market: quarterly reporting is common in the Gulf exchanges and for US domestic filers, while London and Hong Kong are built around half-yearly and annual reports. Foreign private issuers in the US file an annual report on Form 20-F. Some exchanges require structured electronic filing; DFM, for example, charges a separate XBRL registration fee under its fees list. Each report must be consistent with the accounting policies set out in the prospectus, and any change has to be explained.
Investor relations and corporate actions
Investor relations becomes a permanent function: a results calendar, earnings calls, meetings with analysts and funds, a website section with all disclosed documents. Analysts' coverage after the IPO depends on liquidity and interest; small companies sometimes find that coverage fades within a year or two, which affects trading.
Corporate actions follow rules too. Dividends, share buybacks, rights issues, significant acquisitions and related party transactions may require announcements, shareholder approval or independent advice. These rules are changing. Under the 2024 UK Listing Rules, shareholder votes on most significant transactions on the LSE Main Market were replaced by announcements. AIM's revised rules effective 5 August 2026 raised the substantial transaction threshold from 10% to 25%.
Continued listing and delisting
Listing requirements apply on an ongoing basis, not only at admission. If free float, market value or governance falls below the continuing standards, the exchange can impose a marker, move the company to a lower category, suspend trading or cancel the listing. Some current examples from exchange rules:
- HKEX: since 1 January 2026, companies whose public float falls below the threshold receive a -PF marker and have 18 months to restore it.
- DFM: accumulated losses of 50% of capital or a 6-month suspension move a company to Category Two.
- Nasdaq: a USD 5 million minimum market value continued listing standard took effect on 23 July 2026, with accelerated delisting below it.
- AIM: a company without a Nomad is suspended, and admission is cancelled after 6 weeks if none is appointed.
A company can also choose to leave the market through a voluntary delisting, typically after a takeover or a buyout by the controlling shareholder. Most exchanges then require shareholder approval and protections for minority holders. Planning for the long life of a public company starts before the IPO, in the governance and reporting systems built during readiness.