Slow is the new fast when it comes to economic growth.

While the Schwab IMPACT 2015 conference opened with rays of optimism, two eminent fund managers doused attendees with cold water Wednesday afternoon.

Jeff Gundlach, CEO and co-founder of DoubleLine, questioned whether the financial industry was ready for a potential interest rate hike in December.

“Two-thirds of today’s money managers have never experienced a single Fed rate hike,” Gundlach says. “If rates go up, one day later we'll be talking about another raise. Borrowing costs will go up on leveraged portfolio, and everybody has to get small, all at once.”

Continuing an argument against rate hikes he started making in the summer, Gundlach says economic conditions still do not merit a raise.

“We saw the stock markets swoon pretty badly in August and September, and they’ve fully recovered in the U.S. and other places,” Gundlach says. “The credit market, though, is not showing the same green light signals about a strengthening economy.”

He even holds out the possibility of negative interest rates.

"I always thought negative interest rates were impossible, but that's where we are," Gundlach says. "If it happens, go borrow an infinite amount of money on negative interest rates."

While some indicators have turned positive, including an impressive October jobs number, other indicators are flat.

“Real GDP isn’t going up,” Gundlach says. “The GDP forecasts get lower every year;, what you’re seeing is a triumph of hype over experience. There’s not enough GDP to go around. Nominal GDP has decreased after it peaked in the early 1980s. 2015 will be the second largest contraction of global GDP. There isn’t GDP to go around.”

Contributing to the global malaise, oil prices are likely to move sideways, Gundlach says, because inventories continue to rise.

“People calling for oil to rebound don’t know what they’re talking about,” Gundlach says. “The futures curve bears that out; oil will stay below $60 through 2022. If that happens, you have real problems.”

Bill Priest, founder, CEO and portfolio manager for Epoch Investment Partners, said that the world economy will continue to grow – but slowly.

“Two percent is the new 4 percent,” Priest says. “It turns out that the U.S. will be the only geography to experience growth.”

Priest was skeptical of emerging market GDP growth numbers and presaged that global macro conditions would worsen as the effects of the Chinese slowdown bleed over to its trading partners.

“China was the buyer of everything, and commodity markets crash when they don’t do well,” Priest says. “Emerging markets are toast, but the U.S. is hardly affected at all.”

Investors are best off making investment decisions not on economic sector or geographic location, but fundamentals, Priest says.

“Invest in companies, not countries,” Priest says. “I think stocks are the better investment, but if you’re owning equities, you need to hold them, because the slow growth environment will persist. The end of quantitative easing in the U.S. and the U.K. shifts importance from price/earnings multiples to earnings and dividends.”

Priest names ABInbev, AirBus, Kimberly-Clark, Applied Materials and Dow Chemicals as companies that passed his muster.

Gundlach, on the other hand, said investors could find safest harbor in closed-end bond funds.

“One of the interesting thing about the world today is the opportunity to earn big yield.

“One by one, opportunities have been picking up. What’s a little bit troubling is that nobody wants these opportunities,” Gundlach says. “A lot of them are in closed-end funds. Closed-end funds are incredibly cheap; The average closed-end fund is traded at a 10 percent discount and yields 7.71 percent. You can pick a subset that yields 11 percent or 12 percent. We can get 12 percent buying a $100 bill at $85 of its value. That’s a15 percent discount and nobody wants it. You could see 15 to 20 percent returns on closed end funds, it’s a true no-brainer.”