Gundlach also predicted that oil prices will go even lower than they already have this year. Oil markets are in their "second part of the cycle" wherein prices will drop because producers are getting squeezed after oil settled below $80.
Production will see an increase "maybe on the sly" by countries that depend on oil revenue, he said, creating a "vicious cycle" for the commodity's price. He predicted that $70 is the "line in the sand" for West Texas Intermediate: Any drop below that level will lead to a significant fall in price, he said.
He also said an oil price around $75 would suggest that the consumer price index should probably be near zero—meaning that there is no inflation in the economy. At the time of the interview, WTI traded around $76.70.
Read MoreOil traders increase bets on OPEC action
As for bond predictions, Gundlach said his big bet on the future is that U.S. Treasurys' yield curve will flatten "at a level previously thought unthinkable" sometime in 2015 or 2016.
Gundlach has seen nine consecutive months of inflows into his firm, including more than $2 billion in October. DoubleLine's Total Return Bond Fund boasted $1.82 billion in inflows that month, and $5.6 billion so far this year.
Bond fund investments have been in flux since Bill Gross, co-founder of DoubleLine rival Pimco, left his post in September to join the smaller Janus Capital Group. According to data from Morningstar, Pimco saw investors withdraw $48.3 billion in October.