Many people own an Uber app on their smartphone. But you can soon be able to own a piece of the company — by becoming a shareholder. The online ride-hailing giant has filed confidential preliminary paperwork for selling stock to the public. Word of this comes in a report over the weekend in The Wall Street Journal. The newspaper reports Uber filed the documents last week. The timing indicates a public offering may come within the first three months of next year. Uber declined to comment on the Journal report.