LaSalle at Van Buren Chicago, IL 60605 Tel: (312) 786-5600 Fax: (312) 786-8818 Research & Product Development Index Circular IX-05-106 MEMORANDUM Date: December 9, 2005 To: Members and Member Firms Subject: GSTI Semi-Annual Rebalancings

UPCOMING CHANGES
Following the close on Friday December 16, 2005, CBOE will make the following component changes
to the GSTI Indices:

GSTI Composite Index (GTC) Additions Deletion
s OPWV Openwave Systems, Inc. SGTL Sigmatel, Inc. DGIN Digital Insight ACLS Axcelis Technologies SIRF Sirf Technology Holdings, Inc. BORL Borland Software Corp. ANSS Ansys, Inc. PAY Verifone Holdings, Inc. PWAV Powerwave Technologies NVT Navteq Corp. IDXC IDX Systems, Corp. MWY Midway Games, Inc. VCLK ValueClick, Inc. NFLX Netflix Com Inc. SVR Syniverse Hldgs., Inc. UEPS Net 1 UEPS Technologies, Inc. GSTI Internet Index (GIN) Additions Deletion
s VCLK ValueClick, Inc. NFLX Netflix Com Inc. GSTI Multimedia Networking Index (GIP) Additions Deletion
s PWAV Powerwave Technologies SIRF Sirf Technology Holdings, Inc. GSTI Semiconductor Index (GSM) Additions Deletions SGTL Sigmatel, Inc. ACLS Axcelis Technologies GSTI Software Index (GSO) Additions Deletions OPWV Openwave Systems, Inc. BORL Borland Software Corp. ANSS Ansys, Inc. MWY Midway Games, Inc. GSTI Services Index (GSV) Additions Deletions DGIN Digital Insight IDXC IDX Systems, Corp. PAY Verifone Holdings, Inc. SVR Syniverse Hldgs., Inc. UEPS Net 1 UEPS Technologies, Inc.

Furthermore, after the close on Friday, December 16, 2005, CBOE will adjust the share amounts for the
GSTI Indices. The new shares will be available after the close on Wednesday, December 14, 2005.