A reverse stock split couldn't save the satellite radio stock.Shares of Sirius XM Holdings (SIRI 1.58%) were heading lower last month as investors seemed to balk at its reverse split after it was spun off from Liberty Media.Some Wall Street analysts also weighed in with mixed commentary on the stock. According to data from S&P Global Market Intelligence, the stock finished September down 28%.As you can see from the chart, the stock fell sharply in the first half of the month as the broad market pulled back ...