Silvergate shares tumble as the crypto bank's ties to FTX come under a probe by the DOJ's fraud squad

• The DoJ's fraud unit is probing Silvergate's linkages with FTX and its trading arm Alameda, per Bloomberg.
• The crypto-friendly bank hasn't been accused of any crime, but the Justice Department wants to know just how deep its ties with FTX ran. 
• Silvergate's shares fell more than 13% in premarket trading on Friday.

The US Justice Department is investigating Silvergate Capital's ties with FTX and its trading arm Alameda Research, according to a report by Bloomberg.