The debate that has taken added urgency amid the ascent of passive funds.
Its managers are debating whether it's time to move away from so-called secular growth companies.
For the second time this year, trading has exploded on the nation's exchanges.
Unlike gold or silver, a primary source of demand for palladium is from industry.
The mechanism for creating and turning over shares of ETFs needs more automation, Virtu told the SEC in a letter.