South Korea will require people who trade Bitcoin and other virtual currencies to do so under their real names, the country’s government said on Thursday, as part of efforts to curb speculation.

Bitcoin, the best-known virtual currency, has been on a gravity-defying bull run over the past few months. The price of a Bitcoin started the year at around $1,000 and topped $19,000 earlier this month, causing swarms of ordinary savers around the world to get in on what remains a largely unregulated — and highly volatile — investment.

Nowhere, though, has the frenzy over virtual currencies been as fevered, or as sudden, as in South Korea.

Until recently, markets for Bitcoin and its competitors barely existed in the country. But a spurt of interest has swept up ordinary people from students to retirees. Trading has become so popular that some South Korean exchanges have set up physical storefronts where the uninitiated can learn more and buy in.