[Mainstream Prediction Platforms Reach Record Highs in Trading Volume and Number of Transactions] On December 5, according to Dune data, trading activity on mainstream prediction platforms remains robust, with nominal trading volume reaching $3.495 billion over the past week. Among them, Kalshi, Opinion, and Polymarket ranked top three with $1.212 billion, $1.096 billion, and $1.083 billion respectively. Additionally, the number of transactions over the past week hit 11.336 million, setting a new historical record.