There are two investor letters that Warren Buffett reads as soon as they are released.

The first is the annual shareholder letter from Jamie Dimon, the chairman and CEO of JPMorgan Chase (NYSE: JPM). In an interview last year, Buffett told Bloomberg that "Jamie Dimon is a fabulous banker, and probably writes the best annual report in America." And in his most recent letter to shareholders, Buffett took the opportunity to explicitly recommend it to Berkshire Hathaway shareholders.

The second are the letters by Howard Marks, the founder and chairman of Oaktree Capital Group (NYSE: OAK), an alternative investment company that specializes in distressed assets. Buffett stated, "When I see memos from Howard Marks in my mail, they're the first thing I open and read. I always learn something, and that goes double for his book [The Most Important Thing: Uncommon Sense for the Thoughtful Investor]."

Oaktree goes public
Although investors have had the opportunity to invest with Jamie Dimon for some time now, Howard Marks' company only had its initial public offering this week. Given Buffett's feelings toward him, is Oaktree a new issue that investors should buy?

If the market's reception to Oaktree's initial public offering on Wednesday night is any indication, the answer appears to be "no." According to reports, the company had originally intended on selling 10.3 million shares in a range of $43 to $46 a share. When all was said and done, however, it was only successful at pricing 8.84 million shares at $43, raising an estimated $380.3 million. Because the offering represented about 6% of the company's outstanding shares, this values Oaktree at $6.5 billion.

While it certainly didn't help that the market had been down this week on fears from Europe and a dismal March jobs report, the lack of interest in Oaktree's offering is more likely related to the line of business it's in. Namely, because of the convoluted structure of private equity firms, public market investors struggle to value the performance fees in their funds. And it's for this reason that shares in many of Oaktree's peers have performed abysmally since going public.

For example, shares of Blackstone Group (NYSE: BX), the world's largest private equity firm, have lost more than half their value since listing in the summer of 2007. And in the one year that it's been public, Apollo Global Management's (NYSE: APO) shares are down 23% -- though, in both cases, the companies have consistently paid dividends. Indeed, the only major private equity company to see its shares rise since going public in recent years is Kohlberg Kravis Roberts (NYSE: KKR), which listed on the New York Stock Exchange in 2010.

At the end of the day
If investing were like horse racing, then it'd be foolish to pass up the opportunity to invest in a company led by a man that Warren Buffett holds in such high regard. However, as the market's reception of Oaktree demonstrates, there's clearly much more to it than simply picking a horse, if you will. It's business performance that matters most.

It's for this reason that I encourage you to check out one of our newest free reports: "The Stocks Only the Smartest Investors Are Buying." In it, you'll find the name of a major financial institution that Warren Buffett recently invested in, as well as the identity of a smaller firm that he would have likely purchased in his earlier years. To find out what companies I'm referring to, click here now -- it's free.