Inflows into the nine recently launched exchange-traded funds (ETFs) tied to bitcoin have resumed their upward trajectory this week after the cryptocurrency's price bounced back from its dip last week. "The resumption in bitcoin's strong performance is sparking renewed interest in the ETFs," said Todd Rosenbluth, head of research at VettaFi, an analysis firm. The nine funds that made their debut in January pulled in nearly $1 billion in assets in the first two days of this week, according to data from BitMEX Research.