A 'buy bitcoin' sign flashed behind Janet Yellen during a 2017 hearing just sold for $1 million

Lauren DeCicca/Getty Images; Jenny Chang-Rodriguez/BI

• A"Buy Bitcoin" sign held up behind Janet Yellen during a 2017 testimony just sold for over $1 million. 
• Christian Langalis, a then-22-year-old intern who held the sign, decided to sell it to fund his crypto startup.
• Bitcoin has surged more than 2,000% since Langalis photobombed Yellen. 

A sign with "Buy Bitcoin" written in all caps on cheap yellow legal pad that was held up behind Janet Yellen during...