Democrats' midterm sweep sends oil, yields and dollar lower as markets rethink rate path

The day after Democrats seized control of both the House and Senate in the November U.S. midterm elections, Brent crude oil plunged 8.7% to settle at $94.62 a barrel — its lowest close since August — Treasury yields fell, the dollar weakened, and stock markets surged. The question now gripping investors worldwide is whether those moves mark a genuine turning point for interest rates, or a fleeting reaction to a single night's results.

Wednesday's session handed the Dow Jones Industrial Average a 1,569-point advance, equal to a 3% gain — its strongest single-day performance since April 2025 and its best showing after a midterm election since 1982, per CFRA Research data. Finishing the day up 1.58%, the S&P 500 outpaced the Nasdaq, which added 1.44%. The VIX, which measures expectations for volatility, sank almost 20%.

Democrats gained control of both chambers with a decisive margin that exceeded most forecasts and hands the party the ability to challenge President Donald Trump's legislative agenda, constrain war powers, and scrutinize executive spending. Trump retains veto power and executive authority over defence, foreign policy and trade, meaning the new Congress creates friction rather than reversal.

The most immediate market signal came from oil. The war between the U.S. and Iran has been a primary driver of elevated energy prices for nearly nine months, squeezing global refining capacity and pushing up the cost of diesel, gasoline and jet fuel. When Vice President JD Vance posted on X that 'the reason we lost is the war,' traders interpreted it as a sign that the administration might now be more inclined to seek a negotiated exit.

An admission from the Republican camp that the Iran war cost them a clean sweep in the election, which the market has taken to indicate that a swift resolution to the Middle East conflict could help them save face. Trump might relish the opportunity to take all the credit if an end to the war leads to a big drop in energy costs.— Dan Coatsworth, Head of Markets, AJ Bell

The oil-rates link is well-documented. In a research note, Bank of America rates strategist Ralph Axel argued that a rise in oil prices over the following three to six months would probably translate into 'significantly higher interest rates' in the U.S., and especially so in the U.K. and Germany. The reverse logic — that falling oil prices ease inflation and reduce pressure on central banks to keep hiking — is what markets are now pricing in, at least partially.

Money markets on Thursday showed a moderate shift in rate expectations from a week earlier, both in the U.S. and Europe. ECB rate pricing fell 8.7 basis points on the week versus 4.6 basis points for the Federal Reserve, according to CNBC's analysis of LSEG data. According to Jim Reid, global head of macro research at Deutsche Bank, investors are now pricing in roughly 50 basis points of Fed rate increases through 2027, a figure that sits below where it stood before the election.

But scepticism is widespread. By Thursday, crude had begun climbing back, and the Bank of England — which raised rates by 25 basis points on Thursday — offered a pointed reminder of the limits of electoral optimism.

A peace process in the Middle East will not shift all of those elements. Let's wait and see, because we have seen that fall in energy prices over the last 48 hours, but it is a very volatile situation, as we've learnt over the last seven, eight, nine months.— Andrew Bailey, Governor, Bank of England

Bailey noted that energy price pressures stem from a combination of obstructions on the Strait of Hormuz, a shortage in refining capacity, and low European gas storage — structural factors that a ceasefire alone would not resolve. Eurasia Group's Clayton Allen told CNBC that while the Iran war is unpopular domestically, leaving the Middle East without tangible wins would also be unpopular, and he expected an escalation within weeks.

The second channel through which the election is reshaping rate expectations is fiscal policy. Markets have historically associated Democratic control with higher spending, but this time the calculus is different. With Democrats holding Congress and Trump in the White House, the result is divided government — and Wall Street, according to multiple analysts, sees that as a constraint on deficit expansion.

Divided government has generally made it harder for fiscal stimulus to be passed. So, that's eased concerns on the fiscal trajectory a bit.— Jim Reid, Global Head of Macro Research, Deutsche Bank

George Bory, chief investment strategist for fixed income at Allspring Global Investments, told Business Insider that fiscal tightening in 2027 is now more likely, with little chance of new fiscal stimulus and heightened scrutiny of capital expenditure depreciation, tariffs and defence spending. Bory added that a smaller deficit in the coming year "would be good for bond investors." The 10-year Treasury yield fell 13 basis points since Tuesday to 4.83%, according to Business Insider.

Not everyone agrees. Gene Tannuzzo, Columbia Threadneedle's global head of fixed income, warned that Democrats and Trump may find common ground on issues like reversing Medicaid cuts or extending expiring CHIPS Act subsidies — both of which would widen the deficit. Tannuzzo cautioned that "these items both increase deficits at a time when the Treasury market is vulnerable." He added that the result "could steepen the curve and push long-term rates up."

December 11 marks the first real test, when current spending authority runs out. Goldman Sachs analysts say a short-term extension to February or March looks most likely given continued disagreement on spending levels.

The third and most volatile factor is artificial intelligence. Democratic wins in states including Texas — which now has a Democratic governor and senator — raised immediate fears of moratoriums or new restrictions on data centre construction, a sector that has been a primary engine of U.S. economic growth and equity market returns.

We expect Democratic governors in Texas, Georgia, and Michigan to impose conditional moratoria pending new legislation restricting data centers. That legislation could end certain tax breaks, tighten environmental, water, and electricity rules, and make it easier for localities to impose their own moratoria.— Goldman Sachs analysts

Goldman Sachs noted that states where Democrats look likely to introduce restrictions account for 45% of planned U.S. data centre capacity. Nvidia fell more than 3%, CoreWeave dropped nearly 10%, and Nebius fell 6.7% on Wednesday. Shares in an exchange-traded fund that tracks AI infrastructure stocks shed 9% on the day.

The rate implication of an AI slowdown runs in the opposite direction to the fiscal restraint argument: slower AI investment could dampen economic growth, which would push the Fed toward cutting rather than hiking. Berenberg chief economist Holger Schmieding cautioned that reduced AI investment, compounded by the drag from Trump's immigration clampdown, could pull U.S. GDP growth down to approximately 1.5% in 2028, compared with 3.4% in the third quarter of 2026.

AI has been an enormous engine powering the US economy, so any curbs on its future development could threaten to put the brakes on growth.— Kit Rees, Investment Strategist, Quilter

UBS analysts took a more tempered position, contending that expanded congressional oversight will 'not necessarily derail the AI investment cycle' since broad federal restrictions remain subject to legislative and federal constraints. Individual state governments, they added, 'may prove more consequential for individual data center projects than the change in congressional control.'

For Europe, the ripple effects are already visible. Defence stocks fell sharply across the continent — BAE Systems dropped 3.3%, France's Thales fell 2.3%, and Italy's Leonardo dipped 1.0% — as investors assessed what a Democratic Congress scrutinising the Iran war could mean for U.S. defence procurement. Ken Egan, head of European Sovereign Credit at KBRA, observed that Europe is 'heading into winter after months of elevated energy prices, and the full impact is still feeding through to the wider economy,' adding that central banks are watching to see whether those pressures lift wages and prices more broadly or whether softening demand keeps that pass-through in check.

Gold was a clear beneficiary of the dollar's weakness, jumping 3.4% to $4,074.90 an ounce. Dropping 0.3% to 101.52, the US Dollar Index touched its lowest level in more than a month. Renewable energy stocks rose on expectations that a Democratic Congress could support clean energy policy, with First Solar up 4.6% and Enphase Energy up 3.7%.

The immediate expectation, according to Business Insider, remains one more rate hike this year — particularly after a strong October jobs report. The longer-term picture is where the election result introduces genuine uncertainty, pulling in three directions at once: lower oil prices argue for easing, fiscal restraint argues for easing, but potential spending agreements and an AI-driven growth slowdown complicate the picture further. AJ Bell's Coatsworth summed up the mood: 'For now, oil has begun to climb back up again, and interest rate expectations have not radically changed from pre-election levels.'

Why it matters — How fast central banks raise or cut interest rates affects mortgage payments, savings returns, business borrowing costs and economic growth for millions of people — and the Democratic midterm sweep has introduced the most significant shift in the rate outlook in months.

Sources differ on Whether the Democratic sweep will ultimately push interest rates lower: Yes — fiscal restraint under divided government and potential oil price decline reduce inflation pressure and rate hike need (businessinsider.com) vs Not necessarily — Democrats and Trump may agree on spending items like Medicaid and CHIPS Act extensions that widen the deficit and push long-term rates up (businessinsider.com)

Sources differ on Whether the Iran war will de-escalate following Democratic congressional gains: Markets are pricing in de-escalation; JD Vance's statement seen as signal Trump may seek a deal (cnbcafrica.com) vs Escalation is more likely; leaving the Middle East without wins would also be unpopular domestically (cnn.com)

Reported by theguardian.com, cnbcafrica.com, reuters.com, morganstanley.com, cnn.com, allianz-trade.com, commbank.com.au, morningstar.com, businessinsider.com