Future of cryptocurrencies in question after plunge in value

It's been a very rough year so far for stocks and other investments as the markets have dropped sharply over the past few months. That plunge has been even larger for cryptocurrencies. Since November, the total market value of all cryptocurrencies combined is down nearly two-thirds, or about $2 trillion. Dion Rabouin of The Wall Street Journal joins William Brangham to discuss.