Platinum-backed exchange traded fund (ETF) holdings increased for the ninth consecutive day yesterday reaching 2.96-million ounces, the highest level on record, the BMO Metals Brief noted on Friday. The report put out by BMO Global Commodities Research addedthat ETF inflows had been strong in the year to date, as investors have seemingly taken a view that palladium may be over-bought and see potential for platinum substitution in auto-catalysts over the mid-term.