Oct 14, 2026 · 30 min
Passive investing’s hidden bet on America and big tech
The Portfolio Reset: Episode 1
Market-cap-weighted funds may offer low costs while quietly concentrating portfolios in the U.S. and its dominant technology companies.
- 1Passive funds still make active choices through index design, market-cap weighting, and the indexes investors combine.
- 2The S&P 500’s decade-long lead helped make U.S. equities feel diversified, even as global portfolios grew increasingly concentrated.
- 3Investors may need to reconsider exposure to private companies and assets excluded from traditional indexes.
Don't miss
The hosts reveal how a supposedly diversified global index can become a substantial bet on U.S. stocks and dominant technology companies.
The brief
The S&P 500 outperformed bonds, property, commodities, emerging markets, and gold over the previous decade, helping cheap passive funds become the default choice for many investors.
Merryn Somerset Webb and John Stepek trace passive investing from John Bogle’s low-cost indexing philosophy to ETFs and online brokerage, which made market exposure easier to buy.
The hosts challenge the idea that passive investing means making no decisions: index construction, market-cap weighting, and fund combinations all shape the risks investors actually own.
A global market-cap-weighted portfolio now carries a large U.S. allocation, with dominant technology companies helping prolonged success make concentration feel like diversification.
The series’ central question is whether the portfolio that worked best over the last decade can deliver the same results in the next one.
What was said on this episode
29 statements · 13 positive · 7 negative · 1 mixed · 8 neutral
Global bonds returned approximately 2.7% over the preceding decade.
“I'd have made in total over 10 years about 2.7%, so $266.”
Listen at 2:28
Global commercial property returned approximately 50% over the preceding decade.
“Global commercial property, I would have made about 50%.”
Listen at 2:47
A basket of commodities approximately doubled in value over the preceding decade.
“I could have gone into a basket of commodities, in which case I would have doubled my money.”
Listen at 2:53
The MXCF emerging-markets index returned approximately 145%.
“I could have gone into emerging markets, the MXCF index, for example, and I would have made 145%.”
Listen at 2:58
Gold outperformed the other listed asset classes over the preceding decade.
“gold would have done better then. All of those, my $10,000 would now be $32,000.”
Listen at 3:13
U.S. stocks, specifically the S&P 500, were the decade’s strongest investment.
“It's US stocks or the S&P 500 to be specific.”
Listen at 3:32
American markets had a stellar year and were at new highs.
“American markets had a stellar year and we're at new highs today.”
Listen at 3:42
An S&P 500 tracker returned more than 310% from August 2016 to the episode date.
“If I put that same $10,000 into a super simple S&P 500 tracker fund, middle of August 2016, I would have $41,000. So I would have made over 310%”
Listen at 4:07
Passive investing has become the default strategy from a formerly niche position.
“And that is why we have seen this massive rise in passive investing. It's gone from something kind of niche to something that is actually the default.”
Listen at 4:48
Past decade returns do not establish what will work during the next decade.
“Those numbers tell you what worked over the last 10 years. They do not tell you what's going to work over the next 10.”
Listen at 5:06
Passive investing is widely perceived as a complete investment solution.
“It's got to the point where everyone thinks that passive investing is itself some solution.”
Listen at 6:01
Passive investing and U.S. outperformance have created underrecognized risks.
“the rise of passive has combined with a lengthy period of outperformance by the US stock market to create risks that many investors may not be entirely aware of.”
Listen at 6:07
Passive investing can produce market concentration in seven companies.
“You end up with what looks like a market concentration in seven companies.”
Listen at 6:16
Investors may need to revise portfolio assumptions and approaches.
“investors building and reviewing portfolios today may need to reconsider their assumptions about the recent past and change their approach accordingly.”
Listen at 6:34
Passive investing was an exceptionally beneficial innovation.
“passive investing was an absolutely brilliant invention.”
Listen at 11:43
Active managers mostly underperform their benchmarks or markets.
“Active managers underperform, which they mostly do.”
Listen at 17:53
Passive investing exceeds half the market by some measures.
“we've passed the point by many measures where it's more than half the market.”
Listen at 18:22
Passive investing has grown from an insurgent to mainstream strategy.
“Definitely getting bigger and bigger, gone from insurgent strategy to mainstream strategy.”
Listen at 18:44
Greater market concentration makes investor portfolios more concentrated.
“the more concentrated the market becomes, the more concentrated investors' portfolios become too.”
Listen at 19:30
The S&P 500’s market-cap weighting is an index-construction decision.
“the S&P 500 is a market cap weighted index. That's a decision.”
Listen at 20:31
Index construction and selection involve numerous judgments.
“there are judgments being displayed everywhere in the construction of the indices, as well as which index you're choosing to follow and which mix of the indices you're choosing to put together.”
Listen at 20:59
Market-cap weighting increases ownership as an asset’s market value rises.
“the more valuable something becomes, the more of it you own.”
Listen at 21:24
U.S. market dominance is primarily driven by dominant technology industries.
“The single biggest reason is that U.S. has tech and those have become dominant global industries.”
Listen at 22:50
A global market-cap-weighted index allocates approximately 70% to America and little to the UK.
“Buy that same index today and you're buying 70% America and almost no UK, for example.”
Listen at 23:22
U.S. market concentration feels sensible but constitutes a concentrated bet.
“This concentration feels sensible because it's been successful. But it is a concentrated bet.”
Listen at 24:16
U.S. exceptionalism could continue for years.
“it could carry on for years, conceivably.”
Listen at 24:48
Concentration among the largest one, five, and ten stocks has reached records and intensified.
“The dominance of the top 1, 5, 10 is the last I checked all-time records. And it has continued to intensify.”
Listen at 25:13
Many investors’ portfolios are less diversified than they believe.
“it's far less diversified than you might currently think.”
Listen at 25:55
Passive investors may need active decisions about portfolio allocation.
“If you want to invest passively, you may need to make some very active decisions about where your money goes.”
Listen at 26:38
Statements are attributed to the speaker as said on the episode and reflect their view at the time, not PodLume's. They are not advice.