https://www.youtube.com/watch?v=QCQ_d0NOF4g; Why Gold Is So Expensive; 6:28; Editor's note: The estimated amount of gold left in Earth’s crust is 55,000 tons, not 55 tons as the video states. Business Insider regrets the error. https://www.youtube.com/watch?v=IBaeWBCuhyQ; A Silicon Valley Founder Shares Advice She Gives To Entrepreneurs; 0:50; Founder of Backstage Capital, Arlan Hamilton, shares the advice she gives to the entrepreneurs she invests in. https://www.youtube.com/watch?v=vI-zJ8bTK0A; How Warren Buffett Makes And Spends His Billions; 5:10; Warren Buffett is the third richest person in the world, but he lives a modest life. He drinks five cokes a day and even eats McDonald's for breakfast. The CEO and chairman of Berkshire Hathaway donates billions to charities. He still lives in the house he bought in the 1950s, which is now worth over $652,000. [Cryptocurrency] https://www.youtube.com/watch?v=_v439vNdsC4; Why central banks are experimenting with blockchain; 2:44; Business Insider spoke to economist Garrick Hileman, from the University of Cambridge, about central banks experimenting with blockchain technology. https://www.youtube.com/watch?v=C9rbAUBePHc; Richard Sherman Is All-In On Cryptocurrencies, But Doesn’t Think His Grandmother Should Invest; 5:06; NFL cornerback Richard Sherman is a paid spokesperson for COBINHOOD, a cryptocurrency exchange with no trading fees. But Sherman's involvement with cryptocurrency started years ago when he started accepting bitcoin for merchandise on his website. Sherman sat down with Business Insider's Sara Silverstein to discuss his view of cryptocurrency. https://www.youtube.com/watch?v=U-Trs5DgJgY; Should You Buy Bitcoin?; 2:25;