Explain what electronic trading systems look like and what they are used for

Electronic systems include exchange order books, alternative trading systems and crossing networks. Order management and execution management systems handle orders and routing, smart order routers send orders to the venues with the best prices, and trading algorithms slice parent orders into child orders to follow schedules such as VWAP or implementation shortfall. Features include direct market access, co-location of servers near exchange engines and advanced order types such as hidden, iceberg and pegged orders. Uses range from executing institutional orders with minimal impact, to market making, arbitrage and news-driven trading. For portfolio managers, the key decision is which algorithm or venue suits the order's urgency and size. A trap is using aggressive algorithms for patient orders.