Privat Capital holds a concentrated portfolio of 16-17 stocks. This strategy forces deep conviction in each position and ensures that winners have a meaningful impact on fund performance. Over-diversification can dilute both research focus and the potential returns from a fund's best ideas.

Analysis of Keynes's portfolio reveals a subtle skill: his true value-add came from ensuring his lowest-conviction ideas received minimal capital. Over his career, his bottom five positions shrank from 11.7% to just 6% of his portfolio, demonstrating a disciplined approach to managing risk on less-certain bets.

Many investors wrongly equate high conviction with making a large initial investment. A more evolved approach is to start with smaller at-cost positions, allowing a company's performance to earn its eventual large weighting in the portfolio. This mitigates risk and improves decision-making.

Instead of using an arbitrary percentage, Gorham Thomason of AKO Capital determines maximum position size based on a stock's liquidity. This ensures the fund can exit a large position without crashing the share price if the investment thesis sours, providing a practical risk management framework.

To manage the perceived risk of a highly concentrated fund, Mohnish Pabrai advises investors to size their position appropriately relative to their total net worth. By recommending investors allocate less than 20% of their wealth to his funds, a single stock representing 50% of the fund becomes a more manageable 10% of the investor's total assets.

To manage risk, GQG determines maximum position size by thinking like a credit analyst. A company with diversified business lines like Exxon can get a "AAA rating" and be a large holding. A more narrowly focused business, despite being attractive, gets a lower rating and a smaller size, preventing concentrated blow-ups.

Allocate more capital to businesses with a highly predictable future (a narrow "cone of uncertainty"), like Costco. Less predictable, high-upside bets should be smaller positions, as their future has a wider range of possible outcomes. Conviction and certainty should drive allocation size.

By seeding new positions at ~0.5% and rarely exceeding 1% at cost, the fund mitigates the behavioral risk of averaging down too aggressively into a failing investment. This disciplined approach prevents a small mistake from becoming a large portfolio loss.

While managers can identify their best ideas within a larger portfolio, this doesn't mean a fund holding only those few ideas will succeed. Empirically, highly concentrated managers often don't outperform. This approach may attract managers whose success is more attributable to luck than skill.