Counterparty risk could hamper trade and worsen a financial crisis. A central clearing party (CCP) insures traders against counterparty default and thus benefits trade. Default of the CCP however becomes a new systemic risk. CCP risk management does not account for risks associated with crowded positions. This paper proposes a CCP exposure measure based on tail risk in trader portfolios. It identifies and measures crowded risk and assigns it to traders according to the polluter pays principle. CCP data show that crowded positions increase CCP exposure most (about one-third) on turbulent days, when exposure is high already.

Fragmented trading is widespread. Chowdhry and Nanda [Chowdhry, B., Nanda, V., 1991. Multimarket trading and market liquidity. Rev. Finan. Stud. 4, 483–511] show that some traders benefit by splitting orders across markets at the cost of small liquidity traders who, for exogenous reasons, only trade locally. We extend their model to analyze British and Dutch stocks with ADRs, which trade on both sides of the Atlantic for one or two hours each day. We predict that, in the presence of sufficient small liquidity trading, traders concentrate their trades in the overlapping period and split orders across markets. We document considerable empirical support. In the cross-section, we find order-splitting only for ADRs with most NYSE small liquidity trading. The evidence is (i) increased volatility, increased volume, and (weakly) higher liquidity supply in the overlap and (ii) positive correlation in order imbalance across markets. We further find that the common component in order imbalance has long-term price impact, which supports the notion that these order-splitters are informed traders.

A faster exchange does not necessarily improve liquidity. On the one hand, speed enables a high-frequency market maker (HFM) to update quotes faster on incoming news. This reduces payoff risk and thus lowers the competitive bid-ask spread. On the other hand, HFM price quotes are more likely to meet speculative high-frequency bandits, and thus are less likely to meet liquidity traders. This raises the spread. The net effect of exchange speed depends on a security's news-to-liquidity-trader ratio.

We model the execution of a large uninformed sell order in the presence of strategic competitive market makers. We solve for the unique symmetric equilibrium of the model in closed form. Analysis of this equilibrium reveals that large orders unequivocally benefit market makers, while smaller investors stand to benefit only if the order trades with a sufficiently high intensity. The equilibrium results further provide a rationale for the empirically observed patterns of (1) shorter orders trading at higher intensities and (2) price pressures potentially subsiding before large orders stop executing.

We study the rivalry between Euronext and the London Stock Exchange (LSE) in the Dutch stock market to test hypotheses about the effect of market fragmentation. As predicted by our theory, the consolidated limit order book is deeper after entry of the LSE. Moreover, cross‐sectionally, we find that a higher trade‐through rate in the entrant market coincides with less liquidity supply in this market. These findings imply that (i) fragmentation of order flow can enhance liquidity supply and (ii) protecting limit orders against trade‐throughs is important.

If bidding in a pure common-value auction is costly and bidders do not know how many others are also bidding, all equilibria are in mixed strategies. Participation is probabilistic, and bid prices are dispersed. The symmetric equilibrium is unique and yields simple analytic expressions. We use them to, for example, show that bid prices exhibit negative skewness. The expressions are further used to estimate the model based on bidding on a Standard & Poor’s 500 security. We find that the number of bidders declined over time, making liquidity supply fragile.