We study Arbitrum's Timeboost mechanism following the adoption of Kairos by its main users -- Wintermute and Selini Capital -- to understand how the emergence of a just-in-time secondary market affects the dynamics of an ahead-of-time primary auction. We find that competition in the primary auction significantly declines and surplus shifts away from Arbitrum. After the transition, bids paid in the primary auction correspond to only 14.8\% of the highest bid (compared to nearly 62.7\% in the \textit{Pre-Kairos} era), and a lower share of searcher profit-and-loss (PnL), despite total PnL (gross of auction payments) remains of similar magnitude across regimes. This indicates that the primary auction effectively ceases to function as a meaningful surplus extraction mechanism. Although demand for time-boosting valuable CEX--DEX arbitrage transactions continues to increase with external price volatility, observed bids in the Timeboost auction no longer reflect this demand. While the exact distribution of the additional value between searchers and Kairos remains unclear, the evidence suggests that the secondary market captures a substantial share at the expense of the primary auctioneer. We conclude by outlining possible ways for Arbitrum to recapture this value, including modifying the auction design to reduce the gap between value and payments and adopting a dynamic reserve price.

翻译：我们研究了Arbitrum的Timeboost机制在其主要用户（Wintermute与Selini Capital）采用Kairos后的演化，以理解即时二级市场的出现如何影响前置一级拍卖的运作动态。研究发现，一级拍卖中的竞争显著减弱，盈余从Arbitrum转移。转型后，一级拍卖中实际支付的出价仅占最高出价的14.8%（相较“前Kairos”时期的近62.7%），搜索者损益份额亦同步降低，尽管总损益（扣除拍卖支付前）在不同机制下保持相近规模。这表明一级拍卖实质上已丧失作为有效盈余提取机制的功能。尽管对高价值CEX-DEX套利交易的时间加速需求仍随外部价格波动持续增长，Timeboost拍卖中观测到的出价已不再反映这一需求。虽然搜索者与Kairos之间额外价值的确切分配尚不明确，但有证据表明二级市场以牺牲一级拍卖方利益为代价攫取了大量份额。我们最终提出Arbitrum重新捕获该价值的可能路径，包括修改拍卖设计以缩小价值与支付之间的差距，以及采用动态底价机制。