My mobile phone was used by someone else to open a stock account.

The biggest possibility is that someone else filled in your mobile phone number incorrectly when opening an account. Next time the salesperson calls you to ask about your stock status, you can ask him which securities company he is from, tell him that his mobile phone number is wrong, and ask him to cancel it. The other ones are scammers and advertisements, trying to get your information and trick you into spending money. If your ID card is used to open an account, congratulations, quickly bring your ID card to a securities company and a third-party bank, freeze the stocks and funds, and wait for the owner to come over for negotiation.