Q: On Fast Money’s trader radar we look at the stock that was lighting up screens across Wall Street. Whether it's the latest Britney Spears tune or Snoop-Dog ditty, this company allows its paying customers access to the music airwaves without commercials. This week, its superstar Howard Stern had something to smile about as the Justice Department approved its merger with a competitor. Who is it?

A: On the trader radar tonight we’re watching Sirius Radio . Shares of this satellite radio company were among the most active on the Nasdaq today and all week.