American Superconductor tumbles after stock offering unveiled

American Superconductor's AMSC.O shares down 14.9% premarket to $29.30 as co looks to raise equity

Ayer, Massachusetts-based power grid systems and solutions provider late Tues announced proposed stock offering

It plans to use net proceeds for working capital and general purposes, including potential acquisitions

Oppenheimer sole bookrunner for offering

With ~39.5 mln shares outstanding, co has roughly $1.4 bln market cap

AMSC shares on Tues closed up 4.1% at $34.45, up 40% YTD

All 3 analysts covering AMSC are bullish with $39 median PT, LSEG data reflects