Prediction markets about the 2026 midterms have surpassed $1.4 billion in trading volume as Election Day fast approaches, according to a new CNN analysis. https://www.cnn.com/2026/10/23/politics/prediction-markets-midterm-elections-kalshi-polymarket?Date=20261023&Profile=CNN&utm_content=1792792815&utm_medium=social&utm_source=twitter