If you can't beat 'em, join 'em.

It's not surprising that mimicking Warren Buffett's moves over the years would leave you well ahead of the pack. That's why it's great news that as an elephant-sized investment vehicle, Buffett's Berkshire Hathaway (NYSE:BRK-A) (NYSE:BRK-B) is required to periodically report some of its investments.

What's Buffett been up to lately? Unfortunately, Berkshire still hasn't made a run for American Express (NYSE:AXP) like I hinted at, but the Oracle did make one move that got a few heads turning. During the quarter, Berkshire started a new position in NRG Energy (NYSE:NRG), a wholesale power generator with its hands in everything from coal-fueled plants to wind energy. The energy business is nothing new for Buffett: Berkshire has been in the industry for years, primarily through its MidAmerican Energy subsidiary.

Other notable moves include scaling back Berkshire's Anheuser-Busch (NYSE:BUD) stake prior to its agreeing to be acquired by InBev last month. Probably not wanting to wager on the outcome of a deal, Buffett took his profits and ran. As a result of the pending buyout, Anheuser-Busch shares are up around 30% year to date. Not bad for cheap beer.

On the addition side, Berkshire added to its existing stake in Ingersoll-Rand (NYSE:IR) and drugmaker Sanofi-Aventis (NYSE:SNY). Nothing too exciting here.

One notable point: The purchases mentioned are only those for which Berkshire's stake is large enough to require disclosure. The three stocks mentioned cost Berkshire only a fraction of the nearly $4 billion it spent buying equities during the quarter. Intrigued? You should be, because that means Buffett spent billions in the last three months buying small amounts of unnamed stocks. That gets me fired up, because it's essentially a testament that Buffett is finding opportunity in today's crazy market.

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Berkshire Hathaway and American Express are Motley Fool Inside Value recommendations. Berkshire Hathaway is a Stock Advisor selection. The Fool owns shares of Berkshire Hathaway and American Express. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Morgan Housel owns shares in Berkshire Hathaway, but none of the other companies mentioned in this article. The Fool has a disclosure policy.