Invesco Aerospace & Defense ETF(AMEX:PPA)

PPA aims to provide broadly defined exposure to the aerospace & defense industry, which may also include firms in non-defense industries. The fund specifically includes NYSE- or NASDAQ-listed companies engaged in operations supporting the US defense, military, homeland security, and space operations. In this narrow, highly concentrated space, the fund managers use size, liquidity, and revenue screens in selecting its constituents. In addition, the fund managers have discretion on any addition or deletions of holdings at any time if they believe such securities no longer represent the funds industry focus. Selected securities are weighted by market-cap and are rebalanced quarterly, employing 10% weight constraints on each individual constituent in an effort to diversify its portfolio.