Markets: a bubble everyone can see.

What happened

From 12 to 16 October, Indonesia's main index fell 14.91%, erasing Rp1.54 quadrillion of market value in five sessions. The Jakarta Globe called it an $85 billion week.

On Friday 16 October alone, it fell 12%, its worst day in 28 years. Trading was halted for half an hour. On Monday it fell another 5.1%, to its lowest since 2020. It's down 43% this year.

The trigger wasn't AI. MSCI, the index company global funds follow, proposed moving Indonesia out of "emerging market" and into "standalone", over concerns about who owns what, and suspected coordinated trading.

SEB's head of Asia strategy, Eugenia Victorino: "Foreign capital is exiting the Indonesian stock market entirely, and the fallout is now being felt in the bond market."

On Wall Street, the Philadelphia Semiconductor Index, the chipmakers behind the AI boom, fell eight sessions in a row, its longest losing streak since October 2008. It is down 16% since 6 October, after rising more than 60% this year. On the last day, all 30 stocks in it fell.

CoreWeave, which rents out AI computing power, fell 12% in a day and about 25% in five. Its bond yields went above 15%. It carries roughly $50 billion in debt.

The Nasdaq-100 lost 5.5% on the week.

Howard Marks, who warned about the dot-com bubble in 2000, told Bloomberg he doesn't think this is one yet. His reasoning: real bubbles form when nobody worries about risk, and right now everyone is asking.

The five biggest tech stocks trade at about 23 times next year's earnings. Just before the 2000 peak, it was about 65. But the Shiller CAPE, a long-run measure of how expensive the whole market is, sits near 41. The 1999 record was 44.

Nvidia, Apple and Microsoft make up about 21% of the S&P 500. In 1999, it took nearly 10 companies to get there.

Strategist Brian Reynolds says cycles end in the credit market, not the stock market: when investors face margin calls they can't meet.

JP Morgan estimates more than $6 trillion is needed for AI data centres, energy and chips by 2030. Hyperscalers issued more than $100 billion in bonds in six months. Harvard's Jason Furman estimated AI infrastructure was 92% of US GDP growth in the first half of 2025.

Oliver Wyman modelled a crash like 2000. At today's valuations, it "would wipe out approximately $33 trillion of value", more than US GDP.

Companies have pinned more than 117,000 US layoffs on AI this year.

Bitcoin spent the week between $79,806 and $84,231. Even its lowest point sat above its 50-week moving average, near $77,000, the line it fell under last November.

One analyst on X: "Historically, this means the bottom is in and the new bull market has started."

That average is still falling.

This is not financial advice.

When the $6 trillion comes due, who will be holding it?