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 declines significantly and that Arbitrum captures a smaller share of the value generated around Timeboost. After the transition, paid bids in the primary auction correspond to only 14.8\% of the highest bid (compared with nearly 62.7\% in the \textit{Pre-Kairos} era) and to a smaller share of searcher profit-and-loss (PnL), even though total PnL remains of similar magnitude across regimes. While the exact distribution of the remaining surplus between searchers and Kairos remains unclear, the evidence suggests that a substantial share is no longer captured through the primary auction. More broadly, our findings suggest that ahead-of-time allocation mechanisms may be particularly vulnerable to secondary-market intermediation when competition among dominant participants is weak. We conclude by outlining possible ways for Arbitrum to improve revenue capture and discussing how these lessons may apply to Ethereum L1.

翻译：我们研究了Arbitrum在其主要用户——Wintermute与Selini Capital——采用Kairos后的Timeboost机制，以理解即时二级市场的出现如何影响提前一级拍卖的动态。研究发现，一级拍卖中的竞争显著下降，且Arbitrum在Timeboost相关价值中获取的份额减少。转型后，一级拍卖中的有效出价仅相当于最高出价的14.8%（相比之下，《Kairos前》时期这一比例接近62.7%），且占搜索者损益（PnL）的份额也更小，尽管各制度下总PnL规模保持相似。剩余盈余在搜索者与Kairos之间的确切分配尚不明朗，但证据表明，相当一部分盈余不再通过一级拍卖获取。更广泛而言，我们的发现表明，当主导参与者之间的竞争较弱时，提前分配机制可能尤其易受二级市场中介的影响。最后，我们概述了Arbitrum改善收入获取的可能途径，并讨论了这些经验如何适用于以太坊L1。