What is the term for a runner-up firm that is actively trying to increase its market share?

The term for a runner-up firm that is actively trying to increase its market share is referred to as a market challenger. This type of firm typically holds the second-largest market share in a particular industry and seeks to rival the market leader. Market challengers often engage in aggressive strategies, such as altering pricing, improving product quality, or increasing marketing efforts, to capture a larger portion of the market and potentially displace the leader. By positioning themselves this way, they can leverage their existing strengths and target specific segments of the market, appealing to both existing customers of their competitors and new customers alike.

The distinction between a market challenger and other types of market participants, such as market leaders, market followers, or those operating within a market niche, is important. Each category has different strategies and objectives based on their market position and overall goals.