Also, there is a notable build-up of call options open interest between $46,000 to $50,000. “The larger expiries were at $46,000, $48,000 and $50,000, creating time decay concerns late last week with spot stagnating in the $47,000 to $49,000,” range, Adam Farthing, chief risk officer at B2C2 Japan, said. “Down here [around BTC’s current price], we only have $44,000 and $40,000 with any size on them (open interest 2500 and 1500, respectively), we’ve kind of moved away from the problem down here.”