The term, group, typically refers to a large luxury or watch products company which owns multiple brands.
Since the earliest days of Swiss watch production, brands have banded together into larger groups to improve efficiency, variety, and profitability and control competition. Today, most Swiss, German, French, and Japanese brands are controlled by a few large groups. The largest of these, Swatch Group, controls more than half of the market for high-end watches.
As of 2018, the following large watch groups exist