Shares of Cisco Systems Inc. /zigman2/quotes/209509471/composite CSCO +0.55% slid more than 11% Thursday, on track for their worst day since February 2011, taking a few exchange-traded funds along with them. The iShares North American Tech-Multimedia Networking ETF /zigman2/quotes/209420584/composite IGN -0.38% , with 8.3% of its holdings in the equipment maker, fell 1.1% in the late morning. The First Trust NASDAQ Technhology Dividend Index Fund /zigman2/quotes/209799348/composite TDIV +0.46% , which has 7.2% of its portfolio in Cisco shares, lost 1%. The Invesco Buyback Achievers ETF /zigman2/quotes/203779514/composite PKW -0.15% , which has a 4.8% stake, was down 1.2%. The broader stock market /zigman2/quotes/210599714/realtime SPX +0.67% was flat, while the tech-heavy Nasdaq Composite Index /zigman2/quotes/210598365/realtime COMP +1.09% rose 0.7%.