Launched on 12/19/2005, the Invesco RAFI US 1000 ETF (PRF) is a smart beta exchange traded fund offering broad exposure to the Style Box - Large Cap Value category of the market.What Are Smart Beta ETFs?Market cap weighted indexes were created to reflect the market, or a specific segment of the market, and the ETF industry has traditionally been dominated by products based on this strategy.Market cap weighted indexes offer a low-cost, convenient, and transparent way of replicating market returns, and are a ...