Warren Buffett has made some rather bearish moves in Berkshire Hathaway's (NYSE: BRK.A)(NYSE: BRK.B) stock portfolio in the past few quarters. Most notably, the legendary investor disposed of significant portions of both the Apple and Bank of America investments that have performed extremely well for Berkshire.

Steve Ballmer has an unorthodox investing approach. The former Microsoft CEO is worth $151 billion, per the Bloomberg Billionaires Index, making him the ninth richest person the world. That puts him ahead of famed investor Warren Buffett by a nearly $10 billion margin.

Despite Buffett overseeing stakes in nearly four-dozen securities, the lion's share of Berkshire's invested assets have been put to work in seven top ideas.