A fund chief at $2.6 trillion giant State Street says America's hottest investment product is warpin

State Street Global Advisors, a $2.6 trillion asset manager, is a huge player in the passive-investment movement, developing index and exchange-traded funds that provide cheap ways for Main Street to invest. The passive trend has some people worried that ETFs are warping the stock market. State Street also has an active-investment management business, and a $26 billion investment chief there, Paul Colonna, says passive flows have affected his work. Despite the headwinds, Colonna is...