NEW YORK ( TheStreet) -- There's a lot of buzz surrounding the Pandora ( P) public offering today. Shares were well received with the offering price being bumped higher in recent days. A stock that has suffered in the run up to this offering is Sirius XM Radio ( SIRI), whose paid subscription revenue model potentially finds some increased competition from this upstart.>> Pandora IPO Pressures Sirius XM Shares Many newer model cars have sound systems that integrate with various handhelds. The thinking is that there will be an increase in choices when it comes to where you get your music. Although the fundamental side of the equation is interesting, what's more interesting to me is the charts I see on Sirius and the potential for a larger retrace in the stock price. Let me share those charts with you. On the intermediate-term time frame, Sirius currently has worked higher on a suspect bullish trend. Those trends typically retest the area where the initial break higher occurred and with this chart, one could argue that this has already occurred.