ITA holdings include BA 9.0%, LMT 6.4%, NOC 5.0% and HII 2.4%.

Alternatively, investors can take a look at PowerShares Aerospace and Defense Portfolio (NYSEArca: PPA), which is slightly less top heavy. PPA holdings include BA 6.6%, LMT 6.5%, NOC 4.5% and HII 1.9%. The ETF is up 4.4% year-to-date.

Additionally, the SPDR S&P Aerospace & Defense ETF (NYSEArca: XAR) takes a more equal weight approach. BA is 3.7% of XAR, LMT is 3.5%, NOC is 3.6% and HII is 3.6%. The fund is up 2.5% year-to-date.

iShares U.S. Aerospace & Defense ETF

For more information on the defense sector, visit our aerospace & defense category.