Written by Cormac Nevin

While we run the risk of sounding like a broken record by highlighting the extreme concentration on display in U.S and Global Equity indices, we think that the consequences are too profound for investors to ignore.

Last week witnessed Nvidia, the current darling of U.S equity markets benefiting from the AI infrastructure build-out, surge to become the world’s most valuable listed company. Nvidia’s market capitalisation (the value of all its outstanding shares) briefly eclipsed that of Microsoft on Wednesday before retreating on Thursday. Since 31st December 2022, Nvidia’s market cap has risen by $2.77 trillion (for context, the size of the UK economy is $2.74 trillion). The top five stocks in the S&P 500 Index by weight now constitute a record 27.1% of the Index as of May 2024. For context, this was 16% in August 2018 and only reached 18% at the height of the 2000s dot.com mania. Stock market indices are demonstrating radically reduced levels of diversification.

Such extraordinary share price moves are increasingly consequential in the context of markets now dominated by “passive” investors who only seek to replicate an index and will automatically buy more and more of a given stock as its market cap increases, creating a self-reinforcing dynamic which propels it higher. Over the last month, the largest purchasers of Nvidia stock have been index-tracking marketing participants in the form of Vanguard and BlackRock/iShares, while insiders such as the CEO, Jensen Huang, have been sellers.

The phenomenon of market capitalisation-weighted indices becoming dominated by fewer and fewer stocks is not just limited to the U.S markets. It can also be observed in global equity markets such as the MSCI World Index, which in turn have become dominated by the large U.S names which reduce geographic and sector diversification. For the year to date, the market cap-weighted MSCI World Index has outperformed its Equal Weighted equivalent by +12.9% vs +3.9%. As we have highlighted in the past, the MSCI World Momentum Index is now up a stunning +26.9% as the past winners keep winning!

Under these conditions of extreme concentration and momentum, we think it is exceptionally important to participate in the upside while maintaining our approach of diversification across geographies, across the market cap spectrum and with actively controlled allocations. These sorts of dynamics have a habit of reversing very violently after the last dollar of FOMO flows has been spent.


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The information contained in this document is not to be regarded as an offer to buy or sell, or the solicitation of any offer to buy or sell, any investments or products.  

The content of this document is for information only. It is advisable that you discuss your personal financial circumstances with a financial adviser before undertaking any investments.  

All the data contained in the communication is believed to be reliable but may be inaccurate or incomplete. Unless otherwise specified all information is produced as of 24th June 2024. 

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