AIM (Alternative Investment Market) is the LSE's market for smaller, growing companies with lighter regulation than the Main Market.
AIM vs Main Market
| Feature | AIM | Main Market |
|---|---|---|
| Regulator | LSE (exchange-regulated) | FCA (EU-regulated market) |
| Rules | AIM Rules | FCA Listing Rules |
| Min. market cap | None | Depends on listing type |
| Min. free float | None | 25% (Premium) |
| Trading record | None required | Usually 3 years (Premium) |
| Admission document | AIM Admission Document | Full prospectus |
| Share structures | Dual-class permitted | Restricted (Premium) |
| Mandatory adviser | Nomad (always) | Sponsor (admission only) |
Nominated Adviser (Nomad) Role
Every AIM company must retain a Nomad at all times:
- Guide admission process
- Approve significant transactions
- Review price-sensitive announcements
- Ensure ongoing AIM Rules compliance
- Act as quality gatekeeper
Loss of Nomad = immediate trading suspension until replacement appointed.
Disclosure Requirements
| Requirement | Timing | Notes |
|---|---|---|
| Price-sensitive information | Without delay | Similar to MAR Article 17 |
| Interim financials | Half-yearly | Unaudited acceptable |
| Annual report | Within 6 months | Audited |
| Announcements | Via any service | PIPs not required; most use RNS |
Trading Characteristics
- Platform: SETSqx (periodic auctions + market maker quotes)
- Liquidity: Market makers provide continuous quotes
- Segment codes: AIMQ for SETSqx securities