Assets in exchange traded funds and notes total about $1.2 trillion. [ETF Spotlight: Vanguard Emerging Markets]

“Total AUM is actually up $115 billion with the generally positive performance of capital markets,” Colas wrote in a note Friday.

“ETFs have been the most constant source of new money – notably into U.S. stocks – for several years, especially as compared to mutual funds. Consider that thus far in 2012, mutual fund managers have seen $22 billion in outflows from domestic equity mutual fund products, only partially offset by $4 billion of fresh capital into foreign equity funds,” the strategist added. “Compare that with the $20 billion of new money into equity ETFs thus far for 2012, and it is easy to see that ETFs are adding to available capital at a faster rate than mutual funds are shrinking that same pool of money.”

Full disclosure: Tom Lydon’s clients own GLD and VWO.