Can an H1 visa holder own a piece of a US company?
Yes, an H-1B Visa holder may start their own business or own shares of someone else’s business. If starting their own business they must be careful though as there are certain risks and they could have their Visa revoked. As an H-1B Visa holder is employed in the United States they must remain under the employment of the employer listed in their petition. When starting up your own business, you cannot act as a CEO or participate in the day-to-day activities of the business without risking your Visa being revoked. They can act as an investor or shareholder though and keep their Visa status clean. The benefit of being a shareholder or investor is that you can receive passive income and this does not affect your Visa status. Keep in mind if you do receive any income this way that you must pay taxes on it. 8 C.F.R. § 214.2
Bottom Line: the H1 Visa holder should not quit their day job. Under the terms of your H-1B Visa a holder must remain employed by the company listed on their petition, or risk the Visa being revoked.