LONDON — When Wall Street retreated on Friday after Kevin Warsh’s hawkish Jackson Hole speech pushed September rate hike odds to 48%, the FTSE 100 had a different calculation to make. The London benchmark closed up 0.23% at 10,817.72, a modest advance that reflected something New York investors had no comparable protection from: an index built on energy majors that price in dollars and report earnings in sterling.
Shell PLC and BP PLC, the two British oil and gas companies that together account for a significant share of the FTSE 100’s total market weight, moved higher on Friday as crude oil prices steadied and the weaker pound amplified their dollar-denominated revenues in sterling terms. That currency translation effect is a built-in buffer that the FTSE 100 has long carried and that the S&P 500 does not. When the dollar strengthens on a Fed-hawkish day, London’s energy giants often gain in local currency terms, even when their underlying business conditions have not changed.
The FTSE 250, which tracks mid-sized UK companies more exposed to the domestic economy, also advanced, closing at 24,957.78, up 0.24%. The FTSE 250 is the benchmark analysts typically cite as a more reliable read on British consumer and business sentiment, because its constituents earn more of their revenue at home. Its advance on Friday was more surprising than the FTSE 100’s, and less clearly explicable by the dollar mechanism.
Warsh’s speech, the first major set-piece address of his tenure as Federal Reserve chair, delivered a message of continued commitment to fighting inflation and no signal of an imminent rate cut. The probability of a September rate hike in fed funds futures climbed to 48% after his remarks. In London, the immediate relevance of that number depends on what the Bank of England does independently.
The Bank of England operates under its own mandate, setting interest rates for the UK economy without instruction from Washington. Its Monetary Policy Committee meets on its own calendar and responds to UK inflation data, not the US PCE. The relationship between Fed policy and Bank of England decisions is indirect, transmitted primarily through the exchange rate, through global risk appetite, and through the cost of dollar-denominated commodities that the UK economy consumes. On a day when the Fed’s implied path becomes more hawkish, the pound typically weakens against the dollar, which is exactly what happened on Friday.
That sterling weakness is the mechanism through which Warsh’s speech entered the FTSE 100’s arithmetic. The index’s composition, dominated by multinationals that earn revenues globally, means a weaker pound increases the sterling value of overseas profits when those profits are converted back. Shell and BP are the largest beneficiaries of that effect. HSBC Holdings PLC, another major FTSE 100 constituent with significant dollar exposure through its Hong Kong and US operations, saw the same translation benefit.
AstraZeneca PLC, which regularly contests for the status of largest FTSE 100 constituent by market capitalization, has substantial US revenues from its pharmaceutical operations. Its response to a dollar-strengthening day is similar in direction, adding another layer of cushion to the FTSE 100’s Friday session.
The FTSE 100 is maintained by FTSE Russell, the index provider and subsidiary of London Stock Exchange Group. Its 100 constituents are selected by market capitalization from the London Stock Exchange’s main market, reviewed quarterly, and rebalanced to reflect the UK economy’s listed equity landscape, which looks considerably different from the S&P 500’s. Where the S&P 500 is approximately 30% technology stocks, the FTSE 100 leans heavily on financials, energy, healthcare, and consumer staples. That compositional difference is precisely why the two benchmarks often diverge on days driven by technology-sector news or US monetary policy signals.
For UK pension funds, which hold substantial FTSE 100 exposure as a core equity allocation, Friday’s advance was a small but genuine positive. Funds with global allocations experienced a more mixed picture: UK equity exposure gained while US technology holdings, typically accessed through S&P 500 or Nasdaq-equivalent instruments, fell. The net result depended on each portfolio’s specific weighting, a question that millions of British savers will answer indirectly through their quarterly pension statements.
The week as a whole was positive for the FTSE 100. The broader global lift from Nvidia Corp.’s earnings report on Thursday, which sent the US technology sector sharply higher, provided tailwind for international markets including London. The S&P 500 advanced 0.5% for the week despite its Friday retreat, and the FTSE 100 moved in a broadly correlated direction across the week before diverging on Friday.
That Friday divergence is the more instructive data point. The S&P 500 fell 0.3% on the day. The FTSE 100 rose 0.23%. The gap is not large, but its direction is meaningful: in a rising-rate environment driven by US monetary policy, the FTSE 100’s commodity and financial sector weight acts as a partial offset against the technology-sector compression that hits the S&P 500 hardest. That structural difference does not disappear in a single session, but it shows up in the data.
The FTSE 250’s performance is harder to explain through the dollar lens alone. A weaker pound, which Warsh’s speech helped produce, would normally create cost pressures for domestically focused companies that import goods. The 0.24% advance suggests that UK investors weighed those pressures and found them manageable relative to the broader stability that comes from knowing the Bank of England sets UK rates on UK terms, and is not bound by whatever the Federal Reserve decides in Washington.
What comes next for the FTSE depends on the Bank of England’s September assessment of UK inflation, the path of crude oil prices, and whether sterling stabilizes. Warsh’s speech matters to London, but it is transmitted at one remove, through currencies and commodities rather than through rate expectations applied directly to UK equities. On Friday, that indirectness was a buffer. Whether it remains one depends on how the next round of data reads on both sides of the Atlantic.
Related Posts
