Chinese regulators on Monday declared initial coin offerings illegal, dealing a blow to the latest financial-markets mania and sending the prices of the two leading cryptocurrencies, bitcoin and ether, tumbling. The move by China, which included a call for fundraising activities through the digital tokens to “cease immediately,” follows on the heels of a recent warning by the US Securities and Exchange Commission that it may treat the coins as securities, The Wall Street Journal reports. The regulatory maneuvering occurs as fears have grown about initial coin offerings, which have captured investors’ imagination like dot-com startups once did years ago. Coin offerings this year have raised nearly $1.5 billion, up from $256 million last year, according to research site CoinDesk. Of offerings that have gained since their launch this year, the coins have jumped nearly 28 times in value, on average, according to data from research firm Smith & Crown.