sitting on top of this wealth and getting richer by the day, that doesn't get transformed to income. you don't have to put that on your tax return until you sell your stock generally. >> reporter: and for buffett who said in the past he favored raising taxes for the rich, his wealth grew by $24 billion between 2014 and 2018, and the amount of taxes paid? $23.7 million or just 0.1% of his wealth. buffett telling propublica, tax codes should be changed substa substantially, and huge dynastic wealth is not good for our society. the 25 richest americans were worth $1.1 trillion by the end of 2018. it would take 14.43 million american wage earners to make that amount of wealth. the irs and fbi are investigating this leak. >> any unauthorized disclosure of confidential information is