Univision's $3.5 billion deal to buy Hispanic Broadcasting (HSP) was music to the Spanish-language broadcasting stocks Wednesday morning. But not for long.Shares in Spanish Broadcasting ( SBSA) and Entravision Communications ( EVC - Get Report) leaped at the opening on news of the deal before drifting lower as investors considered the broader picture. At issue is whether the particulars of each company's business live up to the generalized scenario driving the Univision-Hispanic deal: That the Spanish language media market is poised for a boom, and ripe for further consolidation. There was no shortage of investors looking to play the trend: The thinly traded microcap Radio Unica Communications ( UNCA) rose more than 11% Wednesday. But at midafternoon all the sector's big players had given away most or all of their earlier gains, while buyer Univision dropped 17% to $31.15 as investors suffered buyer's remorse vicariously.