The concept of "self-sovereignty" in the context of Bitcoin ownership refers to the idea that individuals who own Bitcoin have full control and autonomy over their funds without relying on any third parties like banks or financial institutions. By holding their own private keys, Bitcoin owners have the ability to transact and store their wealth independently, without the need for permission from any centralized authority. This concept aligns with the decentralized nature of Bitcoin and empowers individuals to have complete ownership and control over their assets.