Net Net: Promoting innovation and managing change
Net Net: Promoting innovation and managing change

Rosenberg: Perma-bears on the 'lunatic fringe'

David Rosenberg, chief economist at Gluskin Sheff & Associates, speaks during an interview in New York, May 6, 2011.
Ramin Talaie | Bloomberg | Getty Images

For the better part of 12 years, David Rosenberg was a rock star among perma-bears, an integral part of a crowd that saw little else but doom ahead for the markets and economy.

Now that he's changed his tune, the Gluskin Sheff senior economist and strategist finds himself a self-proclaimed "pariah," alienated from a group he considers detached from reality.

"There are segments of the perma-bear community that literally live their lives on the lunatic fringe," Rosenberg wrote in his popular "Breakfast with Dave" note he distributes each day to clients.

For Rosenberg to be that way with those who see nothing but trouble ahead is a curious change of events, being that he was once one of their champions. Back in 2010, he penned this analysis, reported on, that said the economy was not merely in recession but rather depression.

Fed not raising rates in 2015: Economist

However, Rosenberg turned bullish a couple years ago—most strongly so in 2014—and a crowd that once saw him as a leader now has turned him into an outcast.

Read MoreThis market trend could be 'very negative'

"This is heavier than religion, the tea party or Red Sox Nation for that matter," Rosenberg wrote Friday. "To these fanatics, if the market rallies, it is due to some unholy alliance somewhere, and if the market dives, it is a case of good triumphing over evil."

Rosenberg noted that prior to his bullish conversion he "was a favorite" of the perma-bear blogosphere, but now he's "a pariah and a subject of jokes and derision."

"I think these guys should subject themselves to a New Year's resolution," he advised, "show respect because there are in fact two sides to every debate."

Read MoreWhy 2015 market looks too good to be true