Recently, billionaire Elon Musk struck a deal to buy Twitter for roughly $44 billion.

However, federal regulators suspected Musk of concealing the facts about this agreement. According to the Securities and Exchange Commission (SEC), the billionaire bought up the company’s stocks secretly to prevent a sharp rise in their value. This lag allowed him to buy more shares at a lower price.

According to people familiar with the matter, the regulator thinks that Musk acquired nearly 9% of Twitter’s stock, making his filing only on April 4. This date is considered belated for disclosure. Notably, in case investors buy 5% or more of a public company's shares, they must file a form revealing their stake within 10 days. Analysts estimated that the entrepreneur had saved more than $143 million by keeping the information in secret.