Howard Marks says the current market offers the 'lowest prospective returns in history'

Howard Marks, Co-Chairman, Oaktree Capital 
David A. Grogan | CNBC

After scoring gains during the nearly seven-month stock rally, investor Howard Marks doesn't like what he sees ahead.

In fact, the head of Oaktree Capital Management said that a slew of factors are conspiring to create as bad of an outlook for making serious gains as he's ever seen.

Chief among what he cites is the low interest rate environment that both helped spur the surge off the late-March lows and will restrict returns going forward. The Federal Reserve cut benchmark interest rates to near zero at the beginning of the coronavirus pandemic and the market has been on fire since, though Marks does not expect that to continue.

"In my view, the lowest interest rates represent the dominant characteristic of the current financial environment, creating the dominant consideration for investors: the lowest prospective returns in history," Marks wrote in his latest note to investors.