Cryptocurrency Bitcoin tumbled below the $24,000 level on Monday trading, following dismal U.S. inflation data. Meanwhile, crypto lender Celsius Network froze transfers and withdrawals. Bitcoin was trading at $23,971 as of June 13, 8:51 a.m. EDT, down over 9.8 percent from its opening at around $26,600—its lowest level in around 18 months. The digital currency is…