SETS (Stock Exchange Electronic Trading Service) is the LSE's electronic order book for the most liquid UK equities, including all FTSE 100 and liquid FTSE 250 stocks.
Trading Schedule
| Phase | Time (UK) | Activity |
|---|---|---|
| Opening Auction | 07:50-08:00 | Price discovery, order accumulation |
| Continuous Trading | 08:00-16:30 | Order matching on price-time priority |
| Intraday Auction | 12:00 | Additional price discovery (selected stocks) |
| Closing Auction | 16:30-16:35 | Official closing price determination |
How Order Matching Works
SETS uses a central limit order book with anonymous electronic matching. Orders execute on strict price-time priority:
- Best-priced orders match first
- Orders at same price match by time of entry
- All trades published immediately
The order book displays the top 5 bid and ask levels in real-time, providing full market depth transparency.
Market Segments
| Segment Code | Description |
|---|---|
| XLON | Main Market premium listed |
| ASQ1 | SETS quote segment |
| Other codes | Specific security characteristics |
Reference Prices
SETS continuously calculates key prices throughout the trading day: