No wild, first-day pop for shares of MVNO Virgin Mobile, the joint venture between Sprint (NYSE: S) and Virgin. After pricing last night at $15, the low-end of the range, shares in the company traded modestly higher, at one point hitting $16.63, before settling around $15.50 early in the day. The underwhelming launch could have been due to the stumbles of other high-profile MVNOs, thus damping enthusiasm for the sector, even if Virgin Mobile (NYSE: VM) itself is making money.