As stated in exchange notice 27/09 NASDAQ OMX Derivatives Markets will, as of June 15, 2009, change the reference price used at standard exercise of stock options from Volume Weighted Average Price (VWAP) to the official closing price (Last Paid) of the underlying share.
In connection to this change NASDAQ OMX will change the time for publication of the official closing price of the underlying share. At present an orderbook summary with the official closing price is published approximately 18.00 CET. After the change the official closing price will be published at the time of the trading state ”Post Trade” in SAXESS at approximately 17.40 CET.
For further information, please see the attached document.
