Sold At "Irrational Exuberance". Still Lost Money | Sam Ro on the Bubble Paradox

In this episode of Excess Returns, we dive deep into one of the most pressing investing debates today: how to think about valuations, profit margins, and artificial intelligence in a market that feels both expensive and transformative. Sam Ro joins Matt Zeigler and Kai Wu for a wide-ranging conversation that explores whether traditional valuation tools still matter, how AI is reshaping corporate economics, and why history suggests investors should be cautious about bubble narratives even when enthusiasm runs high. From profit margins and capital intensity to the future of the Magnificent Seven, this episode focuses on how long-term investors can frame uncertainty without relying on false precision or short-term market calls.Timestamps00:00 Valuations, bubbles, and why timing markets is so hard01:41 Do valuations still matter for investors05:58 S&P 500 valuation levels versus history09:30 Profit margins and why mean reversion has not shown up yet14:39 Household finances, pricing power, and consumer resilience15:47 AI, productivity, and the limits of forecasting economic impact19:15 Valuations adjusted for structurally higher profit margins21:15 Tech multiples, growth expectations, and PEG ratios24:07 Are we in an AI bubble and why that question may not help29:14 Lessons from past bubbles and irrational exuberance30:14 How transformative AI could be compared to past innovations35:20 Massive AI capital spending and the risk of overbuild39:42 Who captures value in AI: builders versus users46:39 Revenue per worker and productivity trends48:00 Dispersion inside the Magnificent Seven51:34 Big tech shifting from asset-light to asset-heavy models59:53 Turnover among top companies over time01:01:10 Why Wall Street price targets miss the point01:04:30 Presidential cycles and market returns01:06:28 Fund manager surveys and why popular risks are often lagging indicatorsTopics coveredHow investors should think about valuations over long time horizonsWhy elevated profit margins may be more structural than cyclicalThe role of AI in productivity, earnings, and competitive dynamicsBubble psychology and lessons from the dot-com eraCapital intensity, overinvestment, and the risk of write-downsWhy AI infrastructure builders may not capture most of the valueWhat dispersion within the Magnificent Seven signals for marketsWhy broad diversification still matters in a rapidly changing market