Market Extra: Private equity may be up next for ETF innovation as State Street celebrates SPY

Romantic pensive woman with long wavy hairs hugging her husband with beard. Elegant couple sitting in cafe with hot cappuccino.

Private equity may be the next frontier for the exchange-traded-fund industry, thirty years after the first U.S.-listed ETF was launched, according to Sue Thompson, head of Americas distribution for SPDR ETFs at State Street Global Advisors.