now, along with the dollar and euro, there is a new currency called the bitcoins. you can't put it in your pocket. it trades only on the internet, and today one of the biggest bitcoin exchanges based in tokyo went bust after it was revealed that hundreds of millions of dollars worth of bitcoins were missing. we asked anthony mason to explain all this. >> reporter: in a manhattan park last fall, a small crowd gathered to buy and sell a new unregulated currency. on their smart phones, they traded a digital money called bitcoins. you're a big believer in this currency. >> i'm a big believer in bitcoins. >> barry silbert is c.e.o. of secretary market. >> i think it's a currency like the u.s. dollar or euro and i think it's a great money transfer network like money gram or western uni.