TIP773: How Systems and Simple Math Shape Better Investing w/ Kyle Grieve

What It Covers

Kyle Grieve explores mental models from systems thinking and mathematics that shape better investing decisions, including feedback loops, kill criteria, power laws, and compounding asymmetry, demonstrating how understanding these forces improves portfolio construction and long-term performance.

Key Questions Answered

• •Feedback Loops & Compounding: Reinforcing feedback loops create exponential growth when interest compounds without interruption. A 15% annual return doubles capital every five years. Investors sabotage compounding by selling winners prematurely, withdrawing funds unnecessarily, or failing to maintain consistent deposits into their portfolios over extended periods.
• •Kill Criteria Framework: Combine state and date into pre-commitment contracts: "If margins aren't 8% by year three, sell." This forces action despite noise. Grieve sold Thermal Energy International after it missed three specific KPIs (37-40 development agreements, $35-37M order intake, $22-24M backlog) rather than waiting indefinitely for improvement.
• •Power Law Returns: Portfolio returns follow extreme distributions where 80% of gains come from 20% of positions. Grieve's top four holdings generated 53% of year-to-date returns from 19 positions. This asymmetry means investors can be wrong 50% of the time and still achieve strong overall performance if winners compound sufficiently.
• •Cone of Uncertainty: Businesses with predictable futures deserve larger position sizes. Costco's customer-focused model creates a narrow cone versus speculative microcaps with wider uncertainty. Start positions at 1.5% for high-uncertainty ideas, then average up as the cone narrows and conviction increases through validated KPIs and demonstrated execution.
• •Scale Challenges: Revenue growth creates non-linear problems that destroy value without proper planning. WeWork spent $1.9B to generate $1.8B revenue growth by scaling without sustainable unit economics. Monitor whether R&D and SG&A expenses as percentage of revenue shrink (economies of scale) or grow (diseconomies) as companies expand operations.