Defining Bubbles by Implausible Assumptions

In this episode of Two Quants and a Financial Planner, Jack Forehand and Matt Zeigler highlight the most important investing insights from recent conversations across the Excess Returns podcast network. Drawing on discussions with Andy Constan, Rob Arnott, Kai Wu, Ben Hunt, Rupert Mitchell, Meb Faber and others, the episode connects ideas across macro, markets, AI, credit cycles and valuation. The conversation focuses on timeless investing principles investors can apply today, including how to evaluate expert opinions, how AI may reshape markets and jobs, what defines a true market bubble, why international stocks may be benefiting from global fiscal spending, and why the best opportunities in markets often come after long periods of underperformance.

Topics covered in this episode

• How to evaluate expert opinions during major market events and filter signal from noise

• Andy Constan’s framework for judging credibility based on experience and confidence

• Why charts showing markets rising after wars are often misleading data mining

• The difference between believing in AI technology and believing AI stocks are good investments

• How AI could both replace and augment human work through the task based structure of jobs

• Rob Arnott’s definition of a market bubble using implausible growth assumptions

• Why many technology leaders ultimately fail to justify the expectations priced into their stocks

• The difference between software companies whose moat is code and those with durable intangible advantages

• How brand, switching costs, distribution and network effects protect enterprise software companies

• Why AI may be one of the most disruptive technologies in history and what that means for markets

• Meb Faber on the myth that the easy money has already been made in international and value stocks

• The behavioral challenge of holding unpopular strategies through long periods of underperformance

• Rob Arnott on why small cap value could outperform large cap growth over the next decade

• Ben Hunt on the point in every credit cycle when lenders say no more

• How rising costs of capital can trigger boom bust credit cycles

• Rupert Mitchell on why global equity markets often follow government fiscal spending

• The growing role of international fiscal policy and capital flows in global market leadership

Timestamps

00:00 Introduction and the idea behind the weekly Excess Returns recap show
03:00 Andy Constan on how to evaluate experts and filter market commentary
11:40 Why charts showing markets rising after wars can be misleading
17:00 Kai Wu on AI technology versus AI investments and the future of work
25:37 Rob Arnott on how to define a market bubble using valuation assumptions
29:35 Kai Wu on software moats, intangible assets and enterprise software durability
35:31 Rob Arnott on how disruptive AI could be for the global economy
39:54 Meb Faber on why the easy money has never been made in markets
43:57 Rob Arnott on small cap value versus large cap growth opportunities
48:39 Ben Hunt on credit cycles and the moment lenders pull back
55:56 Rupert Mitchell on fiscal spending and global equity market performance