What are the halakhot that apply to bitcoin? Is it halakhickly money? What even is the halakhic definition of money? Can bitcoin transactions be made over shabbat? That sort of thing.
Jewish law distinguishes three categories of value: goods, which have inherent value; a note, which is a promise of value from a particular individual; and money, which is abstract value.
You might think that Gold and Silver coins have inherent not abstract value, but as the Chazon Ish said, Gold and Silver have no actual material use. People want them only because they are rare, and that means they have abstract value.
Bitcoin, and the balance in your electronic bank account, are the same: They have only abstract value, and are therefor money in halacha.
PS. It would be pretty hard to actually spend bitcoins on Shabbos since they are electronic only.
Short answer: Bitcoin is the same as money.
Long Answer: Halachically , in the talmid money is anything which is minted and has a face on it. (Talmud bavli shabbat, muuktzeh) the Talmud compares a melted coin and a coin in regards to muktzeh on shabbat. Though the melted coin has value there is no risk of it being used in a transaction. The value of the slug itself might actually go up or down in value causing interest problems. However, business transactions and laws of interest etc are based on anything that can be exchanged for something of value. (You notice this the most at weddings when a hankerchief or pen is used as a method of transferring ownership) Money is muktzeh on shabbat because of it's connection to a contract, and one is not allowed to write on shabbat. Meaning the important thing is the contracts, not the form of money itself. Bitcoins are no different from the usage of credit cards or online shopping or checks where no physical money is transferred.
All cryptocurrencies (bitcoin etc.) are not money and never will be. According to Torah Law (Bava Metzia, where it discusses why money cannot be used for a kinyan / acquisition because a person has his attention on the seal on the money-source needed ) and even secular law. Though they might share some characteristics. There is no government issuing it as currency. No goverment, no judicial branch, no laws, no executive branch. Not money