An Invitation for Bid (IFB) is a solicitation from a company or organization for proposals to complete a specified project.

For example, Invitation Homes Inc. (NYSE:INVH) shareholders have seen the share price rise 89% over three years, well in excess of the market return (67%, not including dividends).

Invitations are still valid at the Clubhouse. But now they perform the same role as, for example, invitations in WhatsApp or other applications, and are not a prerequisite for creating an account.