Bitcoin plunges again, now down more than 28% since Sunday’s all-time high

Other cryptocurrencies also post steep declines in a matter of hours

The price of bitcoin continued its weeklong slump Thursday night, dropping more than $2,100 in a matter of hours. The cyrptocurrency is down more than 28% from its all-time high above $19,500 on Sunday.

Bitcoin BTCUSD, -19.48%   was last trading at $13,694, down more than 12% after peaking at $15,830 earlier in the day. Bitcoin futures BTCF8, -17.74%  on the CME were down for a fourth straight session, off almost 10% at $13,390, and are down about 22% this week.

Other leading cryptocurrencies were also hit hard Thursday night, with ether — which runs on the Ethereum network — down about 8% to $758 and bitcoin’s rival spinoff, bitcoin cash, down more than 20% to $2,969, according to CoinMarketCap.com.

The steep plunge Thursday coincided with the start of the Asian trading day, a pattern reflected throughout the week. One reason for the Asian selloff may be worries following Tuesday’s hack of a bitcoin exchange in South Korea — possibly by North Korea — resulting in Youbit exchange owner Yaipan losing about 17% of its total assets. Some have speculated that Asian buyers had been fueling bitcoin’s rapid ascent in recent months.

On Tuesday, bitcoin fell more than $2,500 at one point before recovering somewhat after Coinbase announced it would start trading bitcoin cash.

 Bitcoin has been no stranger to volatile price swings this year, as its steady climb to record levels has overcome a number of short-term price plunges. Still, bitcoin has skyrocketed about $1,500% this year, for an industry-leading market cap of about $245 billion.