US Midterm 'Blue Wave' Bets Intensify: Stock Futures Slide, Treasuries Rally, A-Share Semiconductors Buck the Trend

Preliminary vote counts after the Nov. 3 US midterm elections, Eastern Time, showed Democrats making a breakthrough in a North Carolina Senate seat. Market bets that a 'blue wave' would sweep Congress quickly heated up and immediately transmitted to equities, foreign exchange and bond markets. Risk assets came under pressure, the dollar weakened, Treasuries rose and Asian stocks fell, all part of the same trading theme; on Nov. 4, A-shares were mixed, with semiconductors and pharmaceuticals bucking the trend, showing that funds were still seeking structural opportunities amid external uncertainty.^[5][6]

From North Carolina Breakthrough to 99%: Blue Wave Bets Jump After Counts

Preliminary vote counts showed Democratic momentum clearly exceeding market expectations. In North Carolina, former Democratic Governor Roy Cooper defeated Trump-backed Republican candidate Michael Whatley in the federal Senate race, breaking the Republican Party's 18-year winning streak in the state's federal Senate elections. Georgia Democratic incumbent Senator Jon Ossoff was expected to win re-election, and in the House, New York Democratic candidate Lasher and Pennsylvania candidate Paige Cognetti were both expected to win. On the prediction platform Polymarket, the probability of Democrats sweeping both chambers of Congress soared to 99%, while Kalshi showed about a 99% probability of Democrats winning the House and about a 98% probability of winning the Senate.^[5]

The North Carolina result was key because it changed the market's judgment on the path to Senate control. After winning North Carolina, Democrats would still need to hold all their own seats and pick up three additional seats from Republicans to control the Senate. The race is still evolving, but the rapid jump in prediction-market probabilities already reflects investors repricing the 'blue wave' scenario, triggering a chain reaction across equities, foreign exchange and bonds.^[5]

The Senate Four-Seat Math: Pricing on Election Day Morning

On election day morning, Polymarket showed a 96% probability that Democrats would retake the House and a 74% probability that they would retake the Senate, while the 'full sweep' contract for Democrats traded at 77%. In its 'midterm election preview' report that morning, Goldman Sachs noted that a Democratic House takeover was largely priced in by the market, and that the Senate was the main source of election-related surprises. The current Senate stands at 53 Republicans and 47 Democrats, so Democrats need a net gain of four seats; with only three, the Senate would be tied 50-50, and Vice President Vance's vote would preserve Republican control.^[1]

The Cook Political Report listed seven Senate races as 'pure toss-ups': Alaska, Iowa, Maine, Michigan, New Hampshire, Ohio and Texas. The latest New York Times/Siena poll showed Democrats leading in Michigan, Texas, Kansas, Maine and Ohio, holding an advantage in Alaska, and only roughly tied with their opponents in Iowa. But Goldman Sachs, citing historical election data, noted that since 2002, in states with a stronger Republican lean, Republican Senate candidates' final performance has on average run about 3 percentage points ahead of pre-election polls; among Republican-held seats, North Carolina was the only one where the Democratic lead exceeded this '3-point safety cushion.' Goldman FX strategist Stuart Jenkins also warned that official Senate results could take days or even weeks.^[1]

An 82% Sweep Probability and Thin Liquidity: Prediction Markets' Credibility Tested Again

Election day data showed that on Polymarket the probability of Democrats sweeping both the Senate and House was about 82%, while Kalshi showed about a 97% probability of Democrats taking the House and about a 78% probability of taking the Senate. Total trading volume on Kalshi for midterm-related bets had reached $1.33 billion, while congressional-related market bets on Polymarket totaled about $145 million, bringing the industry total to more than $1.48 billion, a record high.^[3]

But trading was highly concentrated in a few high-profile Senate seats. The Texas Senate seat attracted about $67 million in bets, with the market implying about a 76% probability that Democratic candidate James Talarico would defeat Republican Ken Paxton; the Michigan Senate seat attracted more than $31 million in bets, with the market showing about an 83% probability that Democratic candidate Abdul El-Sayed would defeat Republican Mike Rogers. By contrast, only five House seats on Kalshi had trading volume above $1 million. ACDC noted that liquidity in almost all midterm-related markets on Polymarket and Kalshi was extremely limited, with bets of just a few thousand dollars enough to significantly move the prediction probabilities of the relevant markets; a Kalshi spokesperson rebutted the conclusion, saying the actual cost of manipulation was far higher than the report described.^[3]

High probability does not equal high certainty. Prediction markets rose to fame in the 2024 US election, but have since shown notable deviations in Brazil's presidential election and Israel's election; in October this year, political bets accounted for only about 1% of combined trading volume on Kalshi and Polymarket, with platform volume growth coming more from sports and cryptocurrency price bets. Concentrated trading and thin liquidity mean that if final results deviate significantly from high-probability bets, the credibility of the prediction-market industry will be severely damaged.^[3]

US Stock Futures Slide, Dollar Weakens: Risk Assets Start Pricing a Blue Wave

After the preliminary vote counts came out, investors' first reaction to a Democratic wave was to reduce risk assets. S&P 500 futures at one point fell 1%, Nasdaq 100 futures extended losses to 2%, Dow Jones Industrial Average futures fell about 156 points, or 0.3%, and VIX futures rose above 20. The dollar index fell more than 0.5% intraday, the Bloomberg Dollar Spot Index dropped 0.4%, the euro rose 0.6% against the dollar to 1.1258, the yen rose 0.5% against the dollar to 157.86, and the Swiss franc led G10 currencies with a 0.7% gain.^[5]

Treasuries were the main beneficiaries of this round. The 10-year US Treasury yield fell about 7 basis points to 4.89%, while the Australian 10-year government bond yield also fell 4 basis points to 5.04%. Asian stocks came under broad pressure: the MSCI Asia-Pacific index fell about 1% to 253.24, Nikkei 225 futures dropped more than 3%, Japan's Topix fell 1.7%, South Korea's Kospi reversed from an intraday gain of as much as 3.2% to a loss of 1.6%, and Australia's S&P/ASX 200 fell 0.3%.^[5]

Behind the market moves is a clear policy logic. Investors generally believe that if Democrats control Congress, they will constrain Trump's tax cuts and pro-business policies while putting stricter regulatory pressure on the technology and artificial intelligence sectors; by contrast, a divided government often means tighter fiscal spending and less federal borrowing pressure, which is positive for government bonds. Wellington Management portfolio manager Brij Khurana said a divided government means the high fiscal spending of recent years will be constrained, which historically has usually been quite favorable for Treasuries; Nomura senior rates strategist Andrew Ticehurst also said that a rising probability of a blue wave is generally seen as bearish for the dollar and bullish for Treasuries.^[5]

Deutsche Bank's Historical Pattern: Post-Midterm Gains Face a Concentration Test

A Deutsche Bank report shows that since World War II, the S&P 500 has risen in the 12 months after every midterm election, with all 20 elections since 1946 positive, an average gain of 14.4% and a median gain of 13.7%; extending the timeframe to 1930, 22 of 24 elections recorded gains, a 92% win rate, with an average gain of 13.0%. By comparison, the probability of gains in all calendar years since 1928 is only 67%, with an average gain of 8.1%. There were only two exceptions, 1930 (down 37%) and 1938 (down 5.1%), both in extreme macroeconomic environments.^[2]

Deutsche Bank attributes the post-midterm gains to the systematic removal of political uncertainty. Uncertainty around election results and policy direction peaks before the vote; after the election, the market buys the 'known outcome,' and the typical midterm outcome is divided government and policy gridlock, which actually reduces the risk of major policy changes. But the report also warns that the current concentration of the S&P 500 exceeds all the above historical samples, with a handful of mega-cap companies contributing the vast majority of index returns; even if most stocks rise, if a few core heavyweight stocks disappoint the market, the index as a whole could still post a decline. This is precisely the most likely way the 92% win-rate record could be broken.^[2]

At the rates-market level, Deutsche Bank's fixed-income team noted that after midterm elections the 10-year US Treasury yield has tended to decline over the past 60 years, especially when the election result produces a 'new divided government' setup, with the decline more pronounced. Historical experience shows that for every 2% drop in the S&P 500 in the week after an election, the 10-year Treasury yield roughly corresponds to a 10 basis point decline. The report also cautioned that the current market-priced rate-hike cycle is one of the mildest in history, and that a return of the actual rate path to historical norms would be a shock to the market.^[2]

A-Share Structural Highlights: Semiconductors and Pharmaceuticals Buck the Trend

On Nov. 4, A-shares traded mixed. The Shanghai Composite surged in the morning before turning negative, while the Shenzhen Component and ChiNext edged higher; as of publication, the Shanghai Composite was up 0.05%, the Shenzhen Component up 0.70% and ChiNext up 0.90%. The semiconductor sector rallied, with semiconductor equipment and advanced packaging concept stocks rising, and the CSI Semiconductor Industry Index up more than 4% in the morning; short-drama gaming, culture and media, biotech and precious metals sectors were active, while telecom, real estate, brokerages and baijiu sectors adjusted. Among baijiu concept stocks, Huangtai Liquor hit a fourth consecutive limit-up, while Jinhui Liquor, Jinzhongzi Liquor, Shede Spirits and Wuliangye followed higher.^[6]

Hong Kong stocks opened lower and moved lower, with the Hang Seng Index down 0.17% and the Hang Seng Tech Index down 0.78%; most heavyweight tech internet stocks retreated, but chip and optical module tech stocks rebounded, and the Hang Seng Biotech Index rose more than 1%. In the bond market, government bond futures generally rose, with the 30-year main contract up 0.12% and the 10-year main contract up 0.05%. In commodities, most domestic commodity futures fell, with fuel oil down more than 5%, Shanghai tin down 3%, caustic soda up more than 3% and iron ore up 1%.^[6]

Against the backdrop of global risk appetite coming under pressure from the US election, the structural activity in technology and pharmaceuticals within A-shares, the adjustment in high-weight tech internet stocks in Hong Kong, and the strength in government bond futures all reflected funds favoring sectors with clearer policy and industrial clues amid external uncertainty, while retaining defensive allocations. The counter-trend performance of semiconductors and biotech also contrasted with rising global expectations of technology regulation and heightened volatility in the AI theme, showing that regional markets are repricing along their own industrial clues.^[5][6]

Summary: A Vote-Count Verification Period and Market Repricing

Overall, the market first traded the change in the policy mix brought by a rising probability of a 'blue wave': Democratic control of Congress means tax cuts and pro-business policies would be constrained and regulatory pressure on technology and AI would rise, while a divided government is more favorable for Treasuries. The high probabilities and thin liquidity in prediction markets, plus the historical patterns and index concentration risks flagged by Deutsche Bank, mean that the election result landing does not equal the complete removal of uncertainty; vote counting in key Senate states, the final outcome of congressional control and the market's repricing of policy gridlock remain points to watch.^[1][2][3][5]

Across markets, the sensitive reaction of Treasury yields and the dollar to the election results has already transmitted to Asian stocks and A-share sector performance. Next, the pace at which official Senate results emerge, the calibration between prediction-market probabilities and final vote counts, and the structural moves in semiconductors, pharmaceuticals and the bond market will jointly test how far this 'blue wave' trade can go.^[5][6]