Sirius XM Holdings Inc. Boosts Subscriber Growth Outlook 14% By: Benzinga via Benzinga September 09, 2014 at 16:45 PM EDT Sirius XM Holdings Inc. (NASDAQ: SIRI) raised its 2014 guidance for net subscriber additions by 16 percent to 1.45 million, from 1.25 ... Read More >> Related Stocks: Siriusxm Holdings Inc