Since joining Best Buy last September, CEO Hubert Joly has launched a major campaign to win back Wall Street. He has given detailed information about the company's poor performance to analysts and his plans to correct it. He has hired former Williams-Sonoma executive Sharon McCollam, a darling among Wall Street, as chief financial officer.

Best Buy even managed to eek a slight gain domestic same store sales during the fourth quarter. Joly's efforts have mostly paid off: since December 2012, Best Buy stock has more than doubled to over $26 per share.

But there is one analyst who has proven himself immune to Joly's charm offensive: Michael Pachter of Wedbush Securities.

Of the 26 analysts tracked by Bloomberg who have issued ratings on Best Buy stock in 2013, Pachter is only one of two who recommend investors dump the stock.

Even more startling is Pachter's 12 year price target for BBY: $9 per share. (The next lowest estimate was $21 by S&P Capital's Ian Gordon.)

$9!!!

That means that when Best Buy stock (which had once surpassed $50 a few years ago) tumbled to as low as $11.20 in early December, Pachter still thought the stock was overvalued.

He did not return a call seeking comment.

Pachter, a long time Best Buy bear, is known for his…uh…strongly worded opinions on the retailer in both his research reports and quotes in the media. He was particularly harsh on former CEO Brian Dunn, whom he called completely unqualified for the job. (Many analysts privately said the same thing but Pachter had no problem saying it publicly.)

But not even a complete leadership change has softened Pachter. He called Joly's credentials "unimpressive," especially to turn around a struggler retailer like Best Buy. Joly is a former CEO of travel and hospitality giant Carlson.

Pachter did profess strong words of praise for McCollam. But Pachter said he continues to doubt Best Buy's turnaround strategy.

Fair enough. A little skepticism is not unwarranted, given Best Buy's struggles in recent years.

But Pachter's research note in February, just before Best Buy released fourth quarter and fiscal 2013 earnings, makes you wonder if the analyst will ever change his mind about BBY.

His estimates weren't just wrong. They were REALLY wrong.

Pachter predicted Best Buy would earn $1.35 per share in the fourth quarter. The company earned $1.64 per share.

Pachter predicted Best Buy's profit margins would fall 170 basis points in the quarter. Best Buy said margins declined 10 basis points. He did say the "magnitude of the decline is only a guess."

But McCollam in January already indicated that gross margins would not dramatically fall. So either Pachter was not aware of the guidance or simply wasn't moved by it.

When Best Buy releases its first quarter earnings next Tuesday, Pachter will no doubt be watching.

But no matter what Joly and McCollam say, don't expect him to change his mind about the stock.