Latency delays intentionally slow order execution at an exchange, often to protect market makers against latency arbitrage. We study informed trading in a fragmented market in which one exchange introduces a latency delay on market orders. Liquidity improves at the delayed exchange as informed investors emigrate to the conventional exchange, where liquidity worsens. In aggregate, implementing a latency delay worsens total expected welfare. We find that the impact on price discovery depends on the relative abundance of speculators. If the exchange with delay technology competes against a conventional exchange, it implements a delay only if it has sufficiently low market share.

Central banks have used asset purchase programs to keep markets operational in times of crisis. We model how central bank asset purchases alleviate dealers' balance-sheet constraints, preventing markets from becoming one sided, improving price efficiency and reducing dealer risk positions. Central banks can fully alleviate dealers' balance-sheet constraints by purchasing assets at their fair value; an action which maximizes welfare when dealers are competitive. However, when there is imperfect competition amongst dealers, a central bank which bears costs from intervening may only purchase assets at a discount. We offer additional analysis on the role of lending programs when dealers have leverage constraints, dealers who are unable to net out all balance sheet costs, and cross-asset impacts from interventions.