For anyone trading in smaller cap companies, price monitoring extensions can be an extremely common occurrence. But what are they? Why do they occur? And are they good or bad? Find out the answers to these questions and more with this article on price monitoring extensions.
What is the role of an auction?
Any discussion on price monitoring extensions must firstly begin by covering auctions. Auctions are small intervals during the regular trading day where the electronic order book is effectively frozen. During this time, orders are collected from the market – known as the Call Period – and the matching algorithm considers the orders that have been entered and calculates the price that the maximum amount of shares can be executed. The intention is to find the most popular and reliable price for a security.
At the end of this Call Period, orders that can be matched are executed in an event referred to as the uncrossing, which takes place within a randomised 30 seconds of the end of the Call Period. However, should the auction fail to generate a reliable price, then a price monitoring extension is generated.
What happens during a price monitoring extension?
Should the preceding auction fail to generate a price within a predetermined percentage above or below the reference price, which is the price just before the stock went into the auction, then a price monitoring extension RNS is automatically released to the market, and the Call Period is extended by another 5 minutes. This extra 5 minutes provides participants the chance to review the prices of the orders that have been entered and if appropriate add, delete or amend.
Should this additional period still fail to generate a reliable price, then a second price monitoring extension is released to the market, and the Call Period is extended by another 5 minutes. On this occasion, should the additional period also fail to generate a price within tolerance levels, then this price will be taken forward and the orders that can be matched will be executed in the uncrossing.
Why might the auction fail to generate an acceptable price?
One reason might be that the share has such a wide spread during that day of trading that the bid and ask price are far away from the mid-price. Given that the majority of AIM companies trade on the SETSqx trading system, where there is no maximum spread requirements, this will likely be the problem in a lot of instances.
Another reason for a price monitoring extenion could be the release of news that has a sudden and significant impact on the price that investors are willing to pay for the company’s shares.
When do price monitoring extensions occur?
Price monitoring extensions occur off of the back of an auction, which take place at different times during the trading day depending on the platform the security is traded on. Therefore, as all AIM-listed companies are traded on either the SETS or SETSqx trading system, price monitoring extensions on the AIM market can occur at the following uncrossing times:
- 08:00 (Opening Auction; SETS)
- 09:00 (First Intra-Day Auction; SETSqx)
- 11:00 (Second Intra-Day Auction; SETSqx)
- 12:02 (Intra-day Auction; SETS)
- 14:00 (Third Intra-Day Auction; SETSqx)
- 16:35 (Closing Auction; SETS & SETSqx)
It is important to point out that price monitoring also takes place during regular trading. Here, again, should a potential execution be more than a defined percentage above or below the reference prices, then no executions at that price will occur and an auction will be triggered instead. The point of this auction is to allow the security’s price to reform in an orderly fashion and then be returned to regular trading.
When it comes to regular trading, the thresholds differ slightly, taking into considering two different prices: the dynamic reference price, and the static reference price. The dynamic reference price refers to the last order book execution price (or previous closing price if more recent) prior to the submission of the incoming order. The static reference price refers to the most recent auction price from the current day. However, where that auction failed to generate an execution, the next automated trade that follows the auction is adopted instead.
This price monitoring functionality during regular trading is thought to protect against large trade-to-trade price movements resulting from trading in thin order books, or through the execution of orders with incorrect details (fat fingers).
What are the degrees of tolerance?
The thresholds applicable are managed from a business perspective at trading sector level. Generally, though, more liquid securities have lower thresholds and less liquid securities have higher thresholds.
Reflecting this, AIM SETS securities typically have a 5% threshold on auctions, whereas AIM SETSqx securities have a 10% threshold. In terms of regular trading, AIM SETSqx securities maintain thresholds used during auctions, whilst SETS securities see their dynamic and static price monitoring thresholds typically increase to 10%.
The most current thresholds for all trading services are set out in this Millennium Exchange Business Parameters document.
What is the purpose of a price monitoring extension?
As already discussed, the extension draws attention to a potential price movement. By doing so, this allows participants to review the prices of the orders that they have entered and if appropriate add, delete or amend.
The extension also indicates to investors that there may be the potential of getting a good deal for the security in question, thereby encouraging their involvement and so stabilising the price through the inputting of acceptable orders.
Ultimately, though, the point of the extension is to ensure any resulting price is a fair reflection of the security.
Are price monitoring extensions good or bad?
Price monitoring extensions can be alarming if you’re not expecting one, or you know it’s a precursor to a drop in share price. Nevertheless, they are there to help remove volatility from the market by slowing down trading and encouraging the market to reach a more considered price rather than moving around on individual trades. Considering the lower levels of liquidity on AIM, price monitoring extensions can be considered, then, an important mechanism to safeguard investors.
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