Co-founder relationships typically fail due to a change gap. This occurs when there's a shift in one founder's commitment, a divergence in vision for the company's future, or when the company outgrows a founder's skills and they fail to evolve with it.

All sorts of business challenges and pivots are survivable. The single terminal failure is running out of cash. Horowitz cites Slack, which was near death after its initial game product failed, as an example. As long as a great founder has capital, they should not be counted out, regardless of current momentum.

A company's runway is not just financial. The failed startup Social Shield had cash in the bank but shut down because the team exhausted all ideas and lost conviction that the problem was solvable, ultimately deciding to return the remaining capital.

VCs can handle pivots and financial struggles. Their primary nightmare is a founder who quits. A startup's ultimate survival hinges on the founder's psychological resilience and refusal to give up, not just market or product risk.

Founder failure is often attributed to running out of money, but the real issue is a lack of financial awareness. They don't track cash flow closely enough to see the impending crisis. Financial discipline is as critical as product, team, and market, a lesson learned from WeWork's high-profile collapse despite raising billions.

Horowitz argues that the critical failure mode for founders isn't making mistakes, but the subsequent loss of confidence. This leads to hesitation on necessary but painful decisions, like reorgs, creating a power vacuum and political chaos that ultimately sinks the company.

Behind every massive success story is a moment where the company nearly failed completely—a 'multiply by zero' event. Whether running out of cash or losing a pivotal deal, successfully navigating these near-death experiences is what separates enduring unicorns from forgotten startups.

A frequent conflict arises between cautious VCs who advise raising excess capital and optimistic founders who underestimate their needs. This misalignment often leads to companies running out of money, a preventable failure mode that veteran VCs have seen repeat for decades, especially when capital is tight.

Founders from backgrounds like consulting or top universities often have a cognitive bias that "things will just work out." In startups, the default outcome is failure. This mindset must be replaced by recognizing that only intense, consistent execution of uncomfortable tasks can alter this trajectory.