Marvin Barth, Barclays' head of FX strategy, says currency intervention just doesn't work. Paul Mortimer-Lee, BNP Paribas' chief economist, says higher bond yields reflect good news. Charles Dumas, TSL Research's chief economist, says the Chinese currency won't slide much more. Finally, Brian Wieser, an analyst at Pivotal Research, says the future of Yahoo depends on tax structure.