Inflation, AI, and Oil: Markets Rediscover the Cost of Capital

Between Wednesday, October 14th, and Friday, October 16th, financial markets received a stark reminder: the era of expensive capital may last longer than expected. US inflation, energy tensions, and doubts about the financial sustainability of the artificial intelligence boom intertwined, generating sell-offs in technology stocks and a renewed revision of interest rate expectations.

The picture has become even more complex with the return of geopolitical risk on oil and with China capable of showing extraordinarily strong trade numbers, while in Europe the International Monetary Fund has indicated the need for further monetary tightening.

US inflation returns to the forefront

The main macroeconomic shock came from the United States. In September, the consumer price index rose 0.6% monthly , bringing annual inflation to 3.7% . The core component, excluding food and energy, also rose to 2.6% , signaling that the problem is no longer solely due to oil.

Energy remains the primary driver of the shock: the sharp increase in fuel prices is gradually spreading to transportation, goods, and services. The following day's data on producer prices reinforced this reading: the PPI jumped 1.3% in a single month and 6.3% year-on-year , the fastest increase in recent years. Services, freight transport, airfares, and distribution margins also showed significant pressure.

For the Federal Reserve, this combination is particularly uncomfortable. Immediately after the CPI data, the market raised the implied probability of a rate hike at the October meeting to 37% , from 22% previously. As the hours passed, the possibility of an immediate tightening diminished, but further action by December became much more credible.

Strong consumers, but not as much as it seems

Further complicating the Fed's task were consumer data. US retail sales rose 0.8% , much more than expected, initially suggesting that demand remained extremely resilient.

The aggregate figure, however, masks a less promising trend. A significant portion of the increase is simply due to higher fuel prices, while "core" sales, which are more representative of the real demand used in calculating GDP, rose by just 0.1% . The American economy thus continues to grow, but a growing share of nominal spending is driven by inflation rather than higher volumes.

Industry, however, retains some strengths. Manufacturing output increased 0.3% in September, and the boom in artificial intelligence investment continues to directly fuel industrial demand: in the third quarter, production of semiconductors and related electronic components grew 28.4% .

Wall Street discovers the fragile side of AI

This apparent contradiction has characterized the stock market. The real economy continues to benefit from technology investments, but the market has begun to question their financial cost.

After the CPI, the S&P 500 lost 1.11% and the Nasdaq 1.88% , with the selling concentrated in technology stocks and companies most exposed to building AI infrastructure.

The problem has suddenly become not the demand for artificial intelligence, which remains very high, but the price required to finance its expansion. Data centers, servers, chips, and energy networks require enormous amounts of capital: if interest rates remain high for longer, heavily leveraged projects inevitably become more vulnerable.

The Philadelphia Semiconductor Index completed its eighth consecutive session of decline on Friday, as the entire chip sector was now significantly correcting from its highs. The selloff also involved companies with solid fundamentals, a sign that the market was reducing exposure to the entire theme rather than picking individual winners and losers.

In this context, Treasuries also regained their defensive function. Despite inflation data that were theoretically negative for bonds, the reduction in portfolio risk led to purchases of US government bonds and a decline in yields. The market thus temporarily favored hedging against equity risk over fears of further Fed hikes.

Oil and geopolitics reignite inflation risk

Oil remains at the root of much of the price pressure. Tensions in the Middle East, Houthi attacks, and risks to Saudi infrastructure have brought the security of global supplies back to the forefront.

Brent crude rose close to $110 a barrel on Friday, supported by fears that further escalation could hit trade routes and regional production.

Adding to this is the Russian-Ukrainian front. Kyiv resumed its attacks on Russian energy infrastructure, targeting the Rosneft refinery in Ryazan, a facility that accounts for nearly 5% of Russian refining . The decision effectively ended the brief truce on energy infrastructure and reminded the market how geopolitical risk is simultaneously distributed across multiple production areas.

Oil thus becomes the link between geopolitics, inflation, and monetary policy: the longer energy prices remain high, the more difficult it will be for central banks to declare the battle against inflation over.

China is racing on exports, Europe is thinking about interest rates

In Asia, China sent a signal diametrically opposed to weak domestic demand. Exports in September grew 36.3% year-on-year, driven particularly by technology, semiconductors, and the automotive sector. The monthly trade surplus reached approximately $134 billion , keeping the country on track to once again surpass $1 trillion for the full year.

However, the strength of Chinese industry also represents a potential new battleground for trade with the United States and Europe, especially in the technology and automotive sectors.

In Europe, however, attention remains focused on inflation. The International Monetary Fund believes that at least another 25 basis point increase in ECB interest rates is necessary by the end of the year, following the tightening already implemented in previous months.

The new balance of the markets

The message emerging from these three sessions is therefore broader than just the Nasdaq's decline. The global economy continues to show strong areas, from AI to Chinese exports, but it must finance this expansion in a context of expensive energy, resilient inflation, and structurally higher interest rates.

The market isn't questioning the ongoing technological transformation. However, it is starting to question the return needed to finance it. And it's the cost of capital, rather than growth itself, that has rapidly returned to the forefront of valuations.