This paper investigates how the introduction of a closing call auction in the OMXS 30 index futures market influences market quality and price accuracy. Index futures markets are characterized by traders with no or little private information. Limit order book models where trader patience (rather...

We exploit an optional colocation upgrade at NASDAQ OMX Stockholm to assess how speed affects market liquidity. Liquidity improves for the overall market and even for noncolocated trading entities. We find that the upgrade is pursued mainly by participants who engage in market making. Those that...