Author: Sean Williams, The Motley Fool

This historically cheap company possesses a number of competitive advantages that makes its stock attractive.

These time-tested companies with rock-solid payouts can pad investors’ pocketbooks for a long time to come.

It’s favored above all others and has been dominating one aspect of the auto industry for more than four decades.

He’s added more than 14.6 million shares of this legal monopoly over a six-month stretch.

Specific regulatory filings, along with the Oracle of Omaha’s investing habits, help narrow down which secret stock Buffett may be purchasing.