Although all crypto-currencies trading ended on Saturday in compliance with China's central bank's ban released in early September, Bitcoin's price recovered from the hammer and reached more than 4,000 US dollars on Monday, a peak price compared to last week.

The Bitcoin price opened at 4,394. 64 US dollars today and currently at around 4,440 US dollars as of press time, according to data from coindesk.com, an information platform for digital assets and blockchain technology. 

China’s central bank banned initial coin offering (ICO) on September 4 and later banned all crypto-currencies exchanges from operating in the country, leading to a wide prices drop in crypto-currency market. 

After the deadline for trading halt, the crypto-currency trading platforms have to give up Chinese yuan and resort to overseas transactions. 

Btcchina.com, one of the major crypto-currency exchanges in China, shows a banner of its US dollar bitcoin trading platform on its front page. 

Btctrade.com, another major exchange in China, also said investors can make transactions on its overseas platform without using yuan. 

Chines authorities are not the only one that recently cast doubts on crypto-currencies, which is not backed by any certain entities. 

Considering the risks of illegal activities, including money laundering and financing of terrorism, Russia’s central bank has claimed crypto-currencies and its derivatives should not be admitted for trading in Russia anytime soon. 

"Given the high risks of circulation and use of crypto-currency, the Bank of Russia considers it premature to admit crypto-currencies, as well as any financial instruments nominated or associated with crypto-currencies, to circulation and use at organized trades and in clearing and settlement infrastructure on the territory of the Russian Federation for servicing transactions with crypto-currencies and derivative financial instruments on them," the central bank said in a statement on September 4.  

The anonymous nature of the trading of crypto-currency, combined with poor security and a lack of investor protections, also pose risks to traders’ assets safety.  

A dozen of traders reported loss of 600 Bitcoins on crypto-currencies trading platforms OKEx and OKCoin in China, with a total value of about 20 million yuan (3 million US dollars), Jiemian.com reported on Monday. 

The victims’ accounts have been hacked from overseas and sold out all Bitcoins in deposit, while the trading platform said it is not responsible for hacking and the victims should resort to police for help, according to the report. 

There have been at least three dozen heists of crypto-currency exchanges in the global market since 2011 and many of the hacked exchanges later shut down, Reuters reported on Friday, noting more than 980,000 bitcoins have been stolen, which today would be worth about 4 billion US dollars.

Doubts on  ICO, a crypto-currency funding mechanism for start-ups, are also growing in many countries, leading to ban or investigation in South Korea, Switzerland and the US.

Related story: South Korea joins global backlash against ICOs