The US Department of Justice has launched a criminal investigation of possible manipulations on the cryptocurrency market, aimed to artificially move up or down the price of bitcoin or altcoins.

The US Justice Department initiated a criminal investigation on bitcoin price manipulations in cooperation with the US Commodity Futures Trading Commission, which oversees the US crypto-based futures market, Bloomberg reports citing four people familiar with the matter.

The purpose of the investigation is to find out whether bidders manipulate bitcoin and other digital currencies prices using illegal methods such as spoofing, or placing fake orders that can encourage other traders to buy or sell cryptocurrency and thereby increase or decrease the price of bitcoin.

The US Justice Department prosecutors suspect that the cryptocurrency markets are are susceptible to fraud and price manipulation, a source told Bloomberg.

Billionaire investor Mike Novogratz greeted the investigation:

“Weeding out the bad actors is a good thing, not a bad thing for the health of the market. Plenty of exchanges have these inflated volume numbers to create some sense of excitement around coins.”

His opinion was echoed by Cameron Winklevoss, president of crypto exchange Gemini, who also welcomed the inquiry.

“This is really welcome news ultimately because this means there is adult supervision coming/here,” Tom Lee, of Fundstrat Global Advisors, said in an email.

As of 24 May, bitcoin continues to fall. The rate of the crypto currency fell below $7,300. Comparing with the peak price of the current month, bitcoin has fallen in price by 20%.