Volterra Semiconductor (VLTR) shares are sharply higher ahead of the company’s fourth quarter earnings report, which is expected after the close. The maker of power management semiconductors is expected to report $19.6 million in revenue and EPS of 8 cents a share. But maybe someone thinks they’ll do better: VLTR shares are up 84 cents, or 10.5%, at $8.84.

Also coming after the close are earnings reports from Atheros (ATHR), Zoran (ZRAN), SanDisk (SNDK), VMware (VMW), Actions Semiconductor (ACTS) and JDA Software (JDAS).