Air carrier First Officer reported a temporary mountain wave encounter which resulted in a high speed exceedance and altitude excursion. The First Officer corrected the aircraft back to assigned altitude and speed.

Narrative

While at cruise with A/P (Autopilot) and A/T (Autothrottles) engaged; we encountered mountain wave that pushed the aircraft into the high speed regime. First initial notice of the event was a speed increase up to just slightly below Mmo. Pilot flying recognized this occurrence; noted that the aircraft had deviated altitude by 200'. Disengaged the autopilot and retarded the throttles while deploying the speed brake. While the aircraft corrected back to the assign altitude the speed then shot dramatically into the red Mmo range delivering an OVERSPEED EICAS warning. Exceedance was less than 15kts above VNE and less than .86 MACH.While in mountain wave at FL330; we experienced an v/s exceed ace of +/-700'; +200' of assigned altitude; +/- 30kts indicated airspeed. This occurrence happened within 15 seconds.