Do you consider Bitcoin(or cryptocurrencies) in general a social movement? If you consider so, social movements need a formal organization to support the movement. Is there a formal organization behind Bitcoin?
No,I don't consider Bitcoin/altcoins to be a social movement.
The term "social movement" is more related to political parties,non-profit organizations,human rights movements,religious movements,etc..
Bitcoin is a currency/financial asset and the blockchain technology is a payment network/system.
The Bitcoin/crypto community is definitely NOT a social movement.The people,who own a certain financial asset cannot be called a "social movement" or a "community".
We don't need any formal organization to "stand behind" Bitcoin.