Answer: According to a report published in The Telegraph, Howells began mining bitcoin on his personal laptop in 2009. In 2013, though, “after I had stopped mining, the laptop I had used was broken into parts and sold on eBay,” Howells tells The Telegraph.

He kept the drive he used to collect the bitcoins, “so if bitcoin did become valuable one day, I would still have the coins I mined.”But, while cleaning his home in 2013, he mistakenly put it into a waste bin at his local landfill site in Newport, South Wales, where it got buried. Now, with bitcoin’s value hovering just above $17,000 Wednesday, according to digital-currency website CoinDesk, Howells’ 7,500 lost bitcoins are worth more than $127 million. CoinDesk’s Bitcoin Price Index tracks prices from digital currency exchanges Bitfinex, Bitstamp, Coinbase and itBit. More than four years’ worth of garbage have poured into the dump since his mistake, which would make any recovery effort a significant undertaking. “A modern landfill is a complex engineering project and digging one up brings up all sorts of environmental issues, such as dangerous gasses and potential landfill fires,” Howells says. “It’s a big, expensive and risky project.”