Most of an index's returns come from a tiny fraction of its component stocks (e.g., 7% of the Russell 3000). The goal of indexing isn't just diversification; it's a strategy to ensure you own the unpredictable "tail-event" winners, like the next Amazon, that are nearly impossible to identify in advance.

Contrary to popular belief, the market may be getting less efficient. The dominance of indexing, quant funds, and multi-manager pods—all with short time horizons—creates dislocations. This leaves opportunities for long-term investors to buy valuable assets that are neglected because their path to value creation is uncertain.

In a world of highly skilled money managers, absolute skill becomes table stakes and luck plays a larger role in outcomes. According to Michael Mauboussin's "paradox of skill," an allocator's job is to identify managers whose *relative* skill—a specific, durable edge—still dominates results.

Contrary to the belief that number two players can be viable, most tech markets are winner-take-all. The market leader captures the vast majority of economic value, making investments in second or third-place companies extremely risky.

Today's market is more fragile than during the dot-com bubble because value is even more concentrated in a few tech giants. Ten companies now represent 40% of the S&P 500. This hyper-concentration means the failure of a single company or trend (like AI) doesn't just impact a sector; it threatens the entire global economy, removing all robustness from the system.

Many LPs focus solely on backing the 'best people.' However, a manager's chosen strategy and market (the 'neighborhood') is a more critical determinant of success. A brilliant manager playing a difficult game may underperform a good manager in a structurally advantaged area.

History shows that transformative innovations like airlines, vaccines, and PCs, while beneficial to society, often fail to create sustained, concentrated shareholder value as they become commoditized. This suggests the massive valuations in AI may be misplaced, with the technology's benefits accruing more to users than investors in the long run.

David Swenson's endowment model has two parts: diversified market exposure (beta) and manager outperformance (alpha). While wealth advisors can easily replicate the beta part using low-cost ETFs, they lack the institutional resources to consistently select top-quartile managers who generate true alpha.

The global economy's reliance on a few dominant tech companies creates systemic risk. Unlike a robust, diversified economy, a downturn in a single key player like NVIDIA could trigger a disproportionately severe global recession, described as 'stage four walking pneumonia.' This concentration makes the entire system fragile.