RE: Auction price monitoring11 Feb 2016 11:05
macaumike... the rules governing the actions are extremely complex, Price Monitering Extensions are part of that complexity but nothing to be concerned about. When it happens it auto generates an RNS. Only two extensions are allowed. The following is proably the most easily understandable explanation for the part PME's play in an auction but I doubt you'll ever find anyone who understands the whole she-bang!
PMEs don't exist on the SEAQ system, only on the SETS and SETSqx systems. (MM Electronic systems) To start, we must recall that the whole purpose of an auction is to generate a stable, reliable closing price. PMEs are initiated when the process fails to find one. Without getting too technical, the first PME can be initiated at 16:35, after the end of the typical auction period. It is initiated if the price found during the preceding 5-minute window is significantly different from the reference price. The reference price is the price just before the stock went into auction. If the difference is too significant, 'price tolerance' is said to be broken and the PME is started. The accepted tolerance is dependent upon the section that the company operates in. The initiation of PMEs warrants an immediate RNS to the market. Below is the text found in a PME RNS.
"Auction call extensions give London Stock Exchange electronic order book users a further opportunity to review the prices and sizes of orders entered in an individual security's closing auction call before the execution occurs. A price monitoring extension is activated when the matching process would have otherwise resulted in an execution price that is a pre-determined percentage above or below the price of the most recent automated execution today."
The RNS highlights to potential investors that they may be able to get a good deal buying or selling said stock and this encourages their involvement in stabilising the price through inputting acceptable orders. As with other parts of the auction, each PME is followed by a REP. Should a stable price still not be found following the first PME, a second PME can be initiated at 16:40, but this is the limit. There can only be 2 PMEs: in such an instance, the final closing price will be generated at around 16:45-16:50 when factoring in the REPs. If, during the two PMEs, no further orders are entered, the original auction price will be accepted. This final closing price will remain outside of price tolerance levels.
An example: A stock was trading at -5% at 16:29, just before the auction period. During the auction period, trades get entered at the price equivalent of -20%. This will likely trigger a PME to try and relieve the price intolerance. You may wonder, why should this occur? One reason it may occur is if the share has a wide spread during the day. If the bid price is far below the mid-price, this could trigger it. Alternatively, the company may release a negative RNS at 16:30 that sets off a decline during the auction