CLAYMORE EXCHANGE-TRADED FUND TRUST

Guggenheim BRIC ETF

Guggenheim Defensive Equity ETF

Guggenheim Dow Jones Industrial Average® Dividend ETF

Guggenheim Insider Sentiment ETF

Guggenheim Large Cap Optimized Diversification ETF

Guggenheim Mid-Cap Core ETF

Guggenheim Multi-Asset Income ETF

Guggenheim Raymond James SB-1 Equity ETF

Guggenheim S&P Spin-Off ETF

Wilshire Micro-Cap ETF

Wilshire US REIT ETF

Guggenheim BulletShares 2025 High Yield Corporate Bond ETF

Guggenheim BulletShares 2027 Corporate Bond ETF

(the “Funds”)

Supplement to the Funds’ Prospectus dated December 29, 2016 or September 27, 2017, each as supplemented from time to time.

Guggenheim Investments announced on September 28, 2017, that it has entered into a definitive agreement to sell its exchange-traded funds business to Invesco Ltd. (“Invesco”), a leading global investment management company. As a result, Guggenheim Funds Investment Advisors, LLC, the investment adviser for the Funds, expects to propose to the Board of Trustees (the “Board”) of Claymore Exchange-Traded Fund Trust that it approve a reorganization of each Fund into a newly organized exchange-traded fund advised by an affiliate of Invesco. If approved by the Board, the reorganization of each Fund would be submitted to the shareholders of the respective Fund for their approval.

Claymore Exchange-Traded Fund Trust

227 West Monroe Street

Chicago, Illinois 60606

Please Retain This Supplement For Future Reference.

September 28, 2017 ETF-SUP-T1