Fortune: Warren Buffett Didn't Buy CarMax

071115_Carmax Logo.jpg

Fortune senior editor Alex Taylor III writes in his column today that we shouldn't pay too much attention to Berkshire Hathaway's addition of CarMax to its portfolio because Berkshire Chairman Warren Buffett "wasn't directly involved in the purchase."

The stock gained 7.5 percentto close at $23.48 last Thursday, the day after Berkshire disclosed that it held almost 14 million CarMax shares at the end of its third quarter in September. Berkshire had reported no CarMax holdings as of the end of the second quarter in June. Investors find it profitable to follow a winner, so if Warren Buffett likes a stock, it generally gets a buying boost from imitators.

Taylor, however, believes the CarMax stake was actually bought by Berkshire subsidiary GEICO and its well-known (although not nearly as well-known as Buffett himself) stockpicker Lou Simpson, who is known to operate independently from the home office in Omaha.

Taylor points to:

  • The relatively small size of the investment: At $258 million, the CarMax stake "wouldn't be big enough to interest Buffett."
  • In the filing, "three of the holders of the CarMax shares are associated with GEICO."

Taylor argues that the market appears to be making a distinction between Buffett and Berkshire when it comes to stock picking. He notes CarMax shares have lost their post-filing pop. Current price:

While Taylor may indeed be right that CarMax is a Simpson pick rather than a Buffett pick, I don't think that necessarily makes it less worthy of copycat buying. After all, as Buffett himself has noted, Simpson has an incredible record, along with Buffett's complete trust and support.

Plus, since it is very difficult to separate a Buffett pick from a Simpson pick, imitators have generally had to treat Berkshire Hathaway and Buffett as one and the same.

Indeed, the recent study by two university professors titled Imitation is the Sincerest Form of Flatterymade no distinction between Buffett and Berkshire. It found that over three decades, buying what Berkshire bought put you way ahead of the market.

Questions? Comments? Email me at buffettwatch@cnbc.com