Polymarket's recent upgrade to its CLOB v2 trading platform on April 28 has resulted in a short-term decline in trading activity, according to Dune data. The number of transactions and trading volume on the platform saw a noticeable drop on the day of the upgrade, with daily traded order volumes falling from previous highs. Despite this, active wallet data suggests that user engagement remains robust, with the decline attributed to system upgrades, API transitions, and temporary market-making liquidity adjustments. In contrast, competitor Kalshi has experienced growth during the same period, with trading volumes stabilizing and transaction counts increasing. Kalshi's expansion is driven by U.S. political events, macroeconomic factors, and sports betting, leveraging its regulatory advantages to attract more U.S.-based users and institutional capital.