You won't find me praising Wall Street analysts very often, but sometimes investors can find a diamond in the rough here and there. Morgan Stanley's upgrade of Capital One (COF) this morning, following the lender's announced buyout of Hibernia (HIB), warrants such praise. The analyst raised the rating on COF to buy from neutral.

An upgrade in and of itself never gets me too excited. The next thing I look at is the particular analyst's track record with respect to that individual stock. After all, if they've been dead wrong on a company for years, why should one all of the sudden listen to them now? A little research finds that Morgan Stanley last put a buy recommendation on Capital One shares on May 12, 2004. This bodes well for investors, as you can see from the chart below.

After getting hit hard in early May of last year, Morgan came out and pounded the table when others were fleeing the name. The buy recommendation at $63 was the right call, and I'd be willing to bet few other analysts were making the same conclusion at that time. It looks like we can add the Morgan Stanley's Ken Posner to the list of relevant Capital One analysts.