The iShares Semiconductor ETF SOXX suffered its worst month since 2002. Ed Yardeni says chip stocks now trade at a discount.

The Philadelphia Stock Exchange Semiconductor Index, or SOX, plunged 21% in July for its worst month since October 2008.

The iShares Semiconductor ETF SOXX suffered its worst month since 2002. Ed Yardeni says chip stocks now trade at a discount.