Buying early on in US trade has run bitcoin up 1.4%, or almost $16, to $1,123 a coin. Wednesday's bid has the cryptocurrency higher for a ninth straight session and threatening its all-time high of about $1,161.88.

The recent strength in bitcoin comes amid speculation the Securities and Exchange Commission will approve at least one of the three proposed bitcoin-focused exchange-traded funds despite analyst concerns that none will be approved.

Bitcoin has soared more than 40% since bottoming out on January 11 following word that China was going to begin cracking down on trading of the cryptocurrency. That rally has come despite news that China's largest exchanges would begin charging a flat fee of 0.2% on all transactions and that two of China's largest bitcoin exchanges were blocking withdrawals.

For the year, bitcoin is up about 18%.