Bitcoin exchange service Bitstamp is back open for business after the company had to shut down its operations on Jan. 6 following a security breach.

The America Herald reported on Jan. 11 that Bitstamp called off the operations while the probe into the hacking was on as some of its virtual money was compromised on Jan. 4, leading to a loss of roughly 19,000 Bitcoins worth nearly $5 million. In a message on Jan. 6, Bitstamp authorities announced its decision to shut down temporarily and also informed their customers that the lost Bitcoins represented just a small fraction of their total Bitcoin reserves.

In a blog post on the official website of the exchange, Bitstamp chief executive Nejc Kodric, said, “We are happy to announce that we are back open for business with a newly redeployed website and back-end systems that are safer and more secure than ever.”

According to Bitstamp, most of its Bitcoin reserves are preserved safely in offline storage systems that are out of the hackers’ reach. The London-based exchange also urged its customers not to deposit the virtual coins to their previously issued Bitcoin deposit addresses.

According to the America Herald, the official blog post by Bitstamp released on Jan. 9 did not provide any specific details on the cyber hacking. Bitstamp, the third-largest Bitcoin exchange, accounts for the five percent of transactions involving the virtual currency.

Bitcoin is a payment system invented by Satoshi Nakamoto in 2008 and introduced as open-source software in 2009. The system is peer-to-peer; users can transact directly without needing an intermediary. Transactions are verified by network nodes and recorded in a public distributed ledger called the block chain.

The Bitcoins traded nearly at $290 on Jan. 9, as per the CoinDesk, where the virtual currency had been trading all week.