Investing in companies that perform stock buybacks | Joachim De Zutter
The PowerShares Buyback Achievers ETF (PKW) is based on the NASDAQ US Buyback Achievers Index.
Morningstar gave the ETF a 5 star rating.

"Research done by Ford Equity Research on companies between 1975 and 2003 found that companies that reduced their shares outstanding by at least 5% outperformed the S&P 500 Index 24 of 28 years." -

S&P Capital IQ: Buying Outperformance: Do Share Repurchase Announcements Lead to Higher Returns?

"In the past 20 years that ended March 31, 2014, the S&P 500 Buyback Index had outperformed the S&P 500 in 17 out of 20 years, with most significant excess returns recorded from 2000 to 2002, 2009, and 2013" [...] "The S&P 500 Buyback Index only underperformed during the late stage of the technology bubble (1998-1999) and the early stage of the financial crisis in 2007. For the overall period, the S&P 500 Buyback Index outperformed the S&P 500 by 5.6% per year, with slightly higher volatility" [...] "Because the S&P 500 Buyback Index employs an equal weighting method, we added the S&P 500 Equal Weight Index in the performance comparison to isolate the alpha generated by buyback ratio stock screening. As shown in the figures, the use of the equal weighting method is not a dominant factor in the outperformance, as the S&P 500 Buyback Index delivered a significant excess return over the S&P 500 Equal Weight Index." - Examining Share Repurchasing and the S&P Buyback Indices

In February 2015 the SPDR S&P 500 Buyback ETF (SPYB) was launched based on the S&P Buyback Index, it has a total expense ratio of 0.35%. Also in February 2015 Amundi launched an ETF based on the S&P Buyback Index with a total expense ratio of 0.15%. The latter uses synthetic replication to match the performance of its index. Since February 2015 both ETFs can be traded via BinckBank.