While CEO and COO open-market buys are strong signals, their absence isn't fatal. In Fiserv's case, recent buys from the new CFO, Chief Legal Officer, and a director with a history of successful insider trades provide critical, albeit more nuanced, confirmation of a turnaround from key oversight roles.

In biotech, CEO insider buys are common and not very predictive. The real signal comes from the rest of the management team, especially the CFO. CFOs are typically more bearish and financially disciplined, so their decision to buy company stock is a particularly strong vote of confidence.

Despite massive stock price drops, there is a notable lack of significant insider buying at many SaaS companies. This passivity suggests management and boards may not believe a quick recovery is imminent, preferring to wait for an "all clear" signal before deploying their own capital.

A CFO's large personal investment, despite a significant subsequent stock price decline, indicates strong belief in a turnaround. Newell's strategy of cutting unprofitable product lines to boost profitability is being misread by the market as just falling revenue, creating a potential value opportunity.

A subtle diligence tactic is to ask the CFO direct questions in a joint meeting and see if the CEO lets them finish. A CEO who constantly interrupts reveals a lack of trust in their finance chief, signaling potential dysfunction and misalignment within the executive team.

Insider buying in biotech isn't just a short-term trading signal around an event. The quantitative analysis shows its predictive power lasts for months after the transaction. This implies insiders are buying based on a durable, fundamental belief in the company's science and trajectory, not just upcoming news.

Empirical studies show that the strongest investment returns don't come from insider buying or value investing in isolation. The key is the combination: systematically buying stocks that exhibit C-suite insider purchasing and also rank in the cheapest deciles based on quantitative value metrics.

Warren Buffett's successor, Greg Abel, is investing his entire $15 million salary into Berkshire Hathaway stock. This is a powerful form of "eating your own dog food" that signals ultimate confidence in the company's future to the market, aligning his personal financial success directly with shareholder outcomes.

Holding both CFO and Chief Acquisition Officer titles provides a more measured perspective on M&A. It forces a continuous evaluation of acquisitions against other capital allocation options like technology investment or organic hiring, preventing a "growth at all costs" mindset.