Slumping buyback-linked ETFs could be telling stock investors to sell By: MarketWatch May 02, 2016 at 05:10 AM EDT ETFs tied to buybacks have lagged the market, which could be an early warning sign for investors, writes Conrad de Aenlle. Read More >> Related Stocks: CONSUMER DISC CONSUMERS STA Macy's Standard & Poors 500 Tradr 2X Long Spy Weekly ETF