Shares of Sirius XM tumbled 8% on Thursday after the company announcing its second-quarter results. More than 15 million shares were traded, the stock's heaviest volume since its reverse split in the late summer of last year. The slide pushes its attractive yield to 5.1% and its 2025 earnings multiple below 8. It would be an attractive situation if not for the fact that Sirius XM has all the makings of a value trap.