Our chart this week is on equity markets around the world, illustrating how the 10,077 shares in the FTSE Global All Cap Index had a total market capitalisation of $103.6tn on 31 December 2025.

This can be analysed as $80.7tn (78% of the total) excluding the top 10 stocks and $22.9tn (22%) for the top 10 stocks.

Excluding the top nine US stocks, the Americas had a total market capitalisation of $46.9tn (45%). In Asia Pacific, excluding the largest non US stock, the total was $17.2tn (17%). Europe, the Middle East and Africa (EMEA) accounted for $16.2tn (16%).

The top 10 stocks are led by Nvidia, valued at $4.4tn (4.2% of the total global stock market capitalisation on 31 December 2025), followed by Apple at just over $3.9tn (3.8%), Microsoft on $3.6tn (3.5%), Alphabet A and C shares combined $3.3tn (3.2%), Amazon on $2.2tn (2.1%), Broadcom on $1.6tn (1.5%), Meta A shares on $1.4tn (1.4%), and Tesla on $1.3tn (1.2%).

The tenth stock (and ninth company) is that of Taiwan Semiconductor Manufacturing (TSM), which had a market capitalisation of $1.2tn (1.2% of the global total) on 31 December 2025.

The market capitalisations for Alphabet and Meta shown exclude the values of their non-traded B shares, which means their total equity values were closer to $4.0tn and $1.7tn respectively on 31 December 2025. The FTSE Global All Cap Index also doesn’t include the $1.6tn estimated market value of Saudi Aramco as less than 2.5% of this stock is traded.

If the top 10 stocks are included with their respective regions, the chart would show the Americas with a market capitalisation of $68.9tn (66% of the total), Asia-Pacific with $18.4tn (18%) and EMEA unchanged at $16.2tn (16%).

Not shown in the chart is how market capitalisations are distributed within each global region. The Americas comprise the US with $43.0tn (41.0%) excluding the top nine US stocks, or $64.7tn (62.0%) if they are included, Canada with $3.2tn (3.1%) and Latin America countries with $0.8tn (0.7%).

The market capitalisation of Asia-Pacific country stocks is led by Japan $5.8tn (5.6%), followed by China including Hong Kong with $3.9tn (3.7%), India $2.1tn (2.0%), Australia and New Zealand $1.8tn (1.7%), Korea $1.6tn (1.5%), Taiwan excluding TMS is $1.2tn (1.2%) and ASEAN nations $0.9tn (0.9%). Taiwan including TMS is $2.4tn (2.3%).

In EMEA, EU member country stocks add up to $9.3tn (9.0% of the total), the UK $3.4tn (3.3%), EFTA countries $2.3tn (2.2%), Middle East $1.1tn (1.1%) and Africa $0.4tn (0.4%).

As everyone investing in stock markets should know, individual share values can go down as well as up, which is why diversifying your investments often makes good sense.

However, in the case of global stock markets – and the US in particular – the total value of listed equities around the world are highly dependent on the fortunes (or otherwise) of just nine companies.

Be careful out there.