Why are there text messages recommending stocks? What is their purpose?

Why are there text messages recommending stocks? What is their purpose? Some stock exchange rooms, or small investment companies. These leather bag investment companies are trading stocks every day, ranging from five to six million on a small scale to tens of millions on a large scale, but their purpose is not to make money from the stock market, but to stare at the pockets of retail investors. It doesn't matter to investors who send text messages. They don't have any trading funds and don't even understand stocks. Their job is to go to major platforms and operators to buy the phone numbers of investors, and then send them fraudulent text messages. After getting the mobile phone numbers of shareholders, they began to distribute them in large quantities with machines, and they could send hundreds of short messages a second.