FRANKFURT (dpa-AFX) - This Friday is another big expiry day: On this day, futures contracts on shares and indices expire on the futures exchanges. The term "major expiry" or "quadruple expiry" is used when options and futures on indices and individual shares expire on the same day.

There are a total of four major expiry dates each year, on the third Friday of March, June, September and December. On these dates, share prices and indices can fluctuate noticeably without any major news. Stronger price swings on such days are mainly seen in heavyweight shares in the relevant indices.

Behind these fluctuations are market participants whose deadline for realizing their derivative transactions expires. Large fund or asset managers in particular try to drive prices up to the prices at which they are committed on the futures exchange. As a result, high trading volumes and significant price fluctuations can occur within minutes. Individual small investors can hardly intervene to move prices.

At 12.00 noon, during the so-called fixing, the EuroStoxx 50 and Stoxx 50 index options and futures on Eurex expire first. At 1 p.m., futures and options on the Dax and TecDax expire in the midday auction, followed five minutes later by those on the MDax.

The options and futures on the individual shares then expire towards the close of trading. This applies not only to the German derivatives exchange Eurex, but to most major exchanges worldwide. While derivatives on German and French equities on Eurex, for example, expire at 5.30 p.m., this is already the case in Switzerland at 5.20 p.m./ck/ag/jha/