Claymore Securities, Inc.
2455 Corporate West Drive
Lisle, Illinois 60532


April 16, 2010


Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549


Re: Claymore Securities Defined Portfolios, Series 680

File No. 333-165207


Ladies/Gentlemen:

     The undersigned, Claymore Securities Defined Portfolios, Series 680 (the
"Trust"), by Claymore Securities, Inc., as the sponsor and depositor of the
Trust and of the units covered by the subject Registration Statement, pursuant
to the provisions of Rule 461 of the General Rules and Regulations of the
Securities and Exchange Commission under the Securities Act of 1933, hereby
respectfully requests that the Securities and Exchange Commission consent to the
filing of the amendment to the Registration Statement and grant acceleration of
the effectiveness of said Registration Statement, as amended, so that the same
may become effective as early as practicable on April 21, 2010 or as soon
thereafter as possible.

Very truly yours,

Claymore Securities Defined Portfolios, Series 680

By: Claymore Securities, Inc.


By: /S/ Kevin Robinson
Kevin Robinson
Senior Managing Director, General Counsel
and Secretary