In the DOJ's opinion, an incumbent carrier would need to demonstrate both compelling evidence of capacity constraints and an efficient use of its current licenses in order to gain additional lower frequency spectrum.

ENGADGET

Regulators are looking into whether exchanges, in a rush to gain the business of high-frequency firms, have provided advantages to some sophisticated trading firms that allow them to trade profitably at the expense of other investors, according to people familiar with the continuing probes.

WSJ: High-Speed Trading in the Spotlight