497 1 instlindexxblrstk497.htm INSTITUTIONAL INDEX FUNDS instlindexxblrstk497.htm - Generated by SEC Publisher for SEC Filing
January 24, 2013
U.S. Securities & Exchange Commission
100 F Street, N.E.
Washington, DC 20549
Re: Vanguard Institutional Index Funds (the “Trust”); File No. 33-34494
Pursuant to Rule 497(e) under the Securities Act of 1933, we hereby file exhibits containing
interactive data format risk/return summary information that reflects the risk/return summary
information in the supplement dated January 15, 2013, filed pursuant to Rule 497(e), for Vanguard
Institutional Total Stock Market Index Fund, a series of the above mentioned Trust.
If you have any questions or comments concerning the foregoing, please contact me at
(610) 669-1955.
Tara R. Buckley
Senior Counsel
The Vanguard Group, Inc.
cc: Chad Eskildsen, Esq.
U. S. Securities and Exchange Commission