3. Dealing Flashcards
What shares are traded on SETS?
The shares traded on SETS include:
• Shares in companies within the FTSE All Share.
• ETFs and exchange-traded commodities (ETCs).
• The most traded AIM and Irish securities.
Example companies include BP, GlaxoSmithKline, HSBC and Marks & Spencer.
Define SETS and how does it operates
The Stock Exchange Electronic Trading System (SETS) is a computer system that automatically matches orders to buy and orders to sell equities. It is formally described as an electronic order-driven system.
It operates an electronic order book into which LSE member firms submit their orders to buy and sell equities, and, when there are orders that can be matched, SETS automatically brings them together. The SETS system is available to all LSE member firms, and automatic trading takes place on it between 8.00am and 4.30pm each business day.
What order priority is adopted by SETS?
The order priority adopted by SETS is by price, and then time. The best buy and sell prices are always at the top of the two columns of orders and will be executed first. In the case of the buy orders this is the highest-priced order (315p in the above example, where the order to buy 10,000 shares must have been entered into the system before the order to buy 2,000 shares).
In the case of the sell orders this is the lowest-priced order (316p in the above example). Below the best-priced orders, all the other orders are displayed, giving an immediate picture of the depth of liquidity on the order book.
What happens during the opening auction call period?
At the start of automatic execution on SETS each day there is an opening auction. Leading up to the auction, the period between 7.50am and 8.00am is known as the opening auction call period. In this period no trading takes place; however, three types of order (limit, iceberg and market orders) can be placed on the order book to take part in the opening auction.
When does the auction start on SETS?
The auction itself does not necessarily happen at 8.00am. Instead, it is subject to a random start and will occur at 8.00am plus a random number of seconds between 0 and 30. The auction uses an uncrossing algorithm, through which those orders that overlap on the order book are executed at the single price that maximises the number of shares traded. Simultaneously, the opening price for the security is calculated. During the course of the uncrossing, no further orders can be added and existing orders cannot be deleted or amended.
Name and describe the two possible reasons why the opening auction (SETS) may be delayed.
There is a possibility of the opening auction being delayed beyond its scheduled time. The delay can be caused by either market orders not being fully satisfied, or the price arrived at by the uncrossing algorithm being extreme, or a combination of both of these. The resultant delay is termed an extension.
• A market order extension occurs if there are unexecuted market orders on the order book following the auction. This extension is two minutes plus an additional 0–30-second random end period.
• A price monitoring extension occurs if the opening price is more than the price tolerance level of 5% away from the price of the last automated trade which took place on the previous business day. The price tolerance level is a predefined percentage threshold either side of a base price set by the LSE and currently standing at 5% for the opening auction. The price monitoring extension is five minutes long, again plus an additional 0–30-second random end period.
What is the maximum amount of time an opening auction could be delayed by?
So, there is the potential for a seven-to-eight minute delay to the opening auction if both the market order and price monitoring extensions are applied.
What is the purpose of the Automatic Execution Suspension Period (AESP)
Once the opening auction is complete, automatic execution commences. As orders are entered on to the system, SETS tries to match them. If SETS finds a buyer and seller with agreeable prices and volumes, the trade is automatically executed.
There is a possibility of an interruption to this automatic execution of orders. If the price of a trade is more than the price tolerance level away from the previous trade price, an automatic execution suspension period (AESP) occurs to allow investors time to react to large price changes. The price tolerance level during the continuous trading period varies from 5% to 25%, depending upon the share.
The AESP lasts for five minutes (plus a period of 0–30 seconds) and during this time no trades are executed (although orders can be entered, deleted and amended). Automatic execution then recommences after the uncrossing auction programme is run.
If a SETS security is suspended from trading by the exchange, as with an AESP, no execution takes place, although orders can be entered, deleted or amended.
Detail what happens in SETS between 4 and 4:30
After 4.30pm, when automatic execution is completed, the trading day ends with another auction. The auction call period runs from 4.30pm to 4.35pm, and at 4.35pm (plus a period of 0–30 seconds) the auction uncrossing algorithm is run.
If auction matching occurs in the closing auction, then the day’s closing price will be based on the closing auction price. If no execution occurs, the volume weighted average price (VWAP) of the last ten minutes of continuous trading will be used. In the event of no automatic trades in the VWAP period, the last automatically executed trade price will be used.
For the last 25 minutes until 5.00pm, SETS allows participants to delete orders. No execution takes place during this period.
Name the types of orders that can be entered into SETS (5)
- Limit orders
- Iceberg orders
- Market orders
- Execute and eliminate orders
- Fill or kill orders
Explain Fill or kill orders
can only be entered during automatic execution. They normally have a specified price (although they can be entered without one) and either the entire order will be immediately filled at a price at least as good as that specified, or the entire order will be cancelled (ie, if there are not enough orders at the price specified or better).
Describe Execute and eliminate orders
can only be entered during automatic execution. As with the at best order, this type will execute as much of the trade as possible and cancel the rest. However, unlike an at best order, this order type has a specified price and will not execute at a price worse than that specified.
Define Market Orders
do not specify a price. They are submitted to the order book to deal in a specified number of shares.
Describe Iceberg orders
are a particular type of limit order. They enable a market participant with a particularly large order to partially hide the size of their order from the market and reduce the market impact that the large order might otherwise have. The term comes from the fact that just the top part of the order is on view (the peak of the iceberg); the rest is hidden (the bulk of the iceberg is below the water). Once the top part of the order is executed, the system automatically brings the next tranche of the iceberg order on to the order book. This process continues until the whole of the iceberg order has been executed, or the time limit for the order expires.
Limit Orders
have a price limit and a time limit, eg, a limit order may state: ‘sell 1,000 shares at 360p by next Tuesday’. SETS will attempt to sell these shares at a price no worse than 360p by next Tuesday. Any time limit up to a maximum of 90 days can be put on these orders. If no time limit is placed on the order, it will expire at the end of the day that it is entered. Limit orders can be partially filled, and it is only limit orders that are displayed on the SETS order book.