Can the address you give out to receive payments let someone figure out your private key?
First, what it means: A digital signature shows that the person initiating a transaction controls the private key. The signing process does not reveal the private key.
Why: No central authority can help you reset your private key. The blockchain only recognizes valid signatures, and anyone who gets the private key can transfer the assets at the corresponding address.
To wrap up, the price: $BTC is quoted at 68636.67, 24h -6.72%.
Don't make important transfers over unfamiliar networks, and remember to keep your phone up to date.

Whether to buy is up to you; I'm just sharing.