>> warren buffett, america's second-richest man, is a household name, his son howard not so much. and yet he's the person warren buffett wants to succeed him as chairman of berkshire hathaway, the mega holding company that buffett built. like his father, howard does not live the high life. in fact, he's a farmer who would rather dig up the ground than sit in a boardroom. are you sure he's your son? >> well, i think that's worth checking out. you'll have a big exclusive. [ticking] [bell ringing] >> for 150 years, the floor of the new york stock exchange was the center of the financial world. but today most trading in stocks is done elsewhere by robot computers that buy and sell in microseconds, faster than you can blink an eye. and the computers have done so well that some institutional traders have come to believe that the game is rigged. are humans ever involved in the trading? >> humans are not involved in the trading because humans are way too slow. [ticking] >> there are close to 850,000 of them in the united states, twice the number of atms. the new slot machines, the main att