A single person or entity having control over specific commercial commodity or service or a vertical monopoly in which a group or entity own the means of production, distribution and other levels of the commercial activity,
All of which can be done by increasing the amount of companies that a group or entity runs or acquires.
People seem to forget we used to tell companies “no” about encroaching on other companies or buying them out to have a larger market share literally as anti-monopoly policies.