Active investing, by contrast, does not have a rebalancing...

Active investing, by contrast, does not have a rebalancing effect, as it involves a manager selecting stocks based on what the manager thinks the company is worth and if it is undervalued.

An active manager has regulated internal mandates e.g. they will regularly rebalance their own portfolio weightings up and down to mandated limits or their own internal valuation metrics. It's a fluid exposure / portfolio, not a set and forget. Even if they love a story, they are likely to be mandated to limit exposure to individual companies to reduce portfolio volatility and manage capital risk.