Private markets have soared to $10 trillion in AUM. But why have they underperformed public markets?

Private markets now total about $10 trillion in AUM, but over the last 10 years the S&P 500 has outperformed private equity by roughly 200 basis points, with the S&P at 15.3% versus PE at 13.2% at the end of September. The article highlights heavy concentration in AI-related venture deals and raises uncertainty around potential mega-IPOs from SpaceX, Anthropic, and OpenAI, including whether sufficient capital exists for such offerings and secondary trades. Overall, it is a reflective, data-driven assessment of private-market conditions rather than a direct company-specific catalyst.

Analysis

The important read-through is not that private markets are “bad,” but that their return engine is becoming more cyclical and more flow-dependent just as public markets remain the cleaner liquidity outlet. If the next cohort of mega-cap private names lists, the first-order winner may be less the pre-IPO buyer than the secondary seller who de-risks into scarcity and retail-driven price discovery. That creates a potential reshuffling of alpha from venture/PE selection skill toward timing skill around the public float event.

Second-order, the article highlights a structural overhang for late-stage private valuation marks: if public comps reset even modestly after a blockbuster IPO wave, the discount rates applied to adjacent private assets should widen, not tighten. That matters for managers like HLNE because secondary volumes can rise in a messy market, but monetization quality may fall if “good enough” exit windows become the norm rather than the exception. In other words, more transaction volume does not automatically mean better realizations.

BIRD is the cautionary example of how narrative inflation can outrun fundamentals in both private-to-public and public-to-public migrations. If investors start demanding proof of revenue durability and path-to-margin from AI-adjacent stories, the weakest balance sheets and smallest TAMs get punished first, while the strongest platforms can still absorb capital on brand alone. The real risk is a near-term clampdown in late-stage funding multiples over the next 3-6 months if one or two marquee IPOs underwhelm.

The contrarian take is that the market may be underpricing how disruptive a successful mega-IPO slate could be for incumbents. A strong SpaceX/Anthropic/OpenAI tape would not just validate private valuations; it would likely siphon liquidity from listed megacaps and quality growth names as investors reallocate toward fresh, high-beta duration. That would help “picks-and-shovels” capital allocators in secondaries, but it could also compress returns for public AI leaders if capital rotates faster than earnings delivery.

Key Decisions for Investors

• Long HLNE on a 3-6 month horizon into any increased secondary/IPO activity; thesis is fee-rate and transaction-volume leverage. Add on weakness if markets price in a slowdown, with downside protected by recurring AUM-related earnings.
• Short BIRD as a proxy for weak narrative-based re-rating; use a 1-2 month time horizon or buy puts into any AI-driven squeeze. Risk/reward favors downside if the market starts discriminating between true platform businesses and story stocks.
• Pair long HLNE / short a basket of speculative late-stage growth names (e.g., BIRD, high-beta venture-backed peers) for a relative-value trade on valuation dispersion widening over the next 1-2 quarters.
• For public AI leaders, trim marginal exposure into any major IPO window and rotate into quality cash generators; if mega-IPOs pull capital, the trade is to own earnings certainty rather than duration.
• Watch UBER as a barometer of post-IPO performance normalization in consumer internet: if new listings trade poorly, expect multiple compression in mature growth names over the following 60-90 days; if they trade well, cover shorts quickly.