Christian Langalis, known for his iconic "Buy Bitcoin" sign photo-bombing of Janet Yellen during her Congressional testimony in July 2017, is auctioning off the historic sign on Scarce City, an online marketplace for collectibles, with bidding set to start on April 18 and run for a week. Langalis, who plans to use the proceeds to fund his startup Tirrel Corp, received a private offer of five BTC (approximately $350,000) for the sign, which was created when Bitcoin was trading around $2,400. The auction will culminate in final bids taken in person on April 24 at PubKey, a bitcoin-themed bar in New York City. Langalis's stunt garnered international attention for Bitcoin, though he was escorted out of the hearing room for violating committee rules.