The IPO Trap

+ Charley Ellis, ChatIPO, Rob Arnott, GMO, Citadel, Man & More

Author

The Idea Farm
June 07, 2026

"An IPO is like a negotiated transaction—the seller chooses when to come public—and it's unlikely to be a time that's favorable to you."

— Warren Buffett

Research

Henry Neville studies drawdowns across equities, bonds, gold, trend, value, momentum, and quality. It argues diversification helps, but pain rarely disappears completely: all seven assets have never drawn down together, yet periods with nothing in drawdown are only just above 4% of history.

Source: Bloomberg and Man Group. Date range: July 1926 - May 2026. 

GMO argues Japan’s equity opportunity is still intact after strong recent returns because corporate reform, earnings growth, and shareholder focus continue to compound. Japan trades at a 20% forward earnings discount to the U.S., while small value remains deeply dislocated.

Scott Rubner argues the equity rally is being supported by stronger earnings, robust AI capex, and persistent flow momentum, but the setup is increasingly unusual. The main tension is that investors still feel underinvested even as market leadership stays narrow and positioning driven dynamics intensify.

Rob Arnott and Lillian Wu examine why index funds are not fully passive at the margins. They argue cap weighted indexes can quietly chase momentum, absorb reconstitution costs, and buy stocks after large price moves rather than before them.

This paper shows that 10-year equity market returns are considerably more predictable in relation to price-earnings ratios than previously thought.

LongTail Alpha explains why backtests can look more reliable than they really are. The core warning is that incentives, hindsight, overfitting, unrealistic assumptions and regime change can turn historical performance into a polished but fragile story.

Bonus Content

ChatIPO: Deutsche Bank takes a quick look at OpenAI’s record-breaking IPO plans. Link

AI is rewiring the wealth management business model. BCG explains how firms can adapt. Link

In your quest to make “better” investments, you should accept that even those which are winners in the long run will all endure bouts of underperformance. Link

Bryan Taylor’s annual paper provides comprehensive coverage of the performance of financial markets in 27 countries and 3 global markets. Link

UF’s Jay Ritter’s research has more data on his site about IPOs than anyone.. Link

Podcasts

5/11/2026 - 32 minutes

Baillie Gifford’s Tom Slater talks about his provocative paper, “AI Isn’t Coming for Your Job. It’s Coming for Your Mind,” and why the real risk may be a world that looks more productive while quietly losing the judgement, learning and expertise that make progress possible.

5/28/2026 - 55 minutes

Brendan Greeley explains not only the dollar's surprising history, but also what actually backs the US dollar and gives it purchasing power.

Meb’s Corner

6/5/2026 - 54 minutes

Charley Ellis discusses the investments that built America, the drivers of long term prosperity and lessons from two centuries of economic history.