If you read Michael Lewis’ Flash Boys, you will be particularly interested in the quest for nanosecond speed trading.
“Because the orders are placed from locations around the world, they frequently arrive at the exchange’s computers out of sequence. The new system allows each computer to time stamp an order when it takes place.
As a result, the trades can be sorted and executed in correct sequence. In a networked marketplace, this precision is necessary not only to prevent illicit trading on advance information known as “front-running,” but also to ensure the fair placement of orders.
The importance of technical advances in measuring time was underscored by European regulations that went into effect in January and that require financial institutions to synchronize time-stamped trades with microsecond accuracy.”