Warren Buffett often used the metaphors of castles and moats when talking about investing, pointing to strong companies (the “castle”) that build “unbreachable moats” by generating high profits and maintaining those profits in the long term. In an interview with Morningstar, the founder of Stellar Wealth Partners and author of The Joys of Compounding, Gautam Baid discussed “economic moats and crumbling castles.”

Baird pointed to corporate culture and management strategies as two strategic ways a company can gain a competitive advantage. Investors want to buy into a company that empowers its employees to do good work, as well as businesses that have revolutionized the way consumers use their product. He cited Amazon, Facebook, and Costco as prime examples of companies that have widened their economic moats by emphasizing culture, and built on that advantage long term. “Those that play the long-term game end up maximizing long-term shareholder value,” he told Morningstar, and watching how a company pays heed to stakeholder value maximization is one indicator of that company’s culture.

Buying stock in a company that is in the process of building an economic moat could prove to be profitable in the long run, especially if investors hold onto those shares through any turmoil that might cause panic selling. But it’s equally important to spot “crumbling castles”—companies whose main business is losing relevance amongst consumers. Even if a crumbling castle has a moat, it’s virtually irrelevant and “high market share in itself is not a moat,” Baid stressed in the interview, citing automobile makers who aren’t gearing up for a transition to electric vehicles as an example of a crumbling castle.

It’s important that investors “exercise active patience,” Baid told Morningstar, holding onto companies while also continuously reevaluating them in order to act swiftly if something “materially adverse” arises that changes a wide moat into a crumbling castle.