** Semiconductor parts maker AXT Inc AXTI.O shares down 11.8% at $69.50 before the bell as $550 mln follow-on offering prices
** Fremont, California-based AXTI sells ~8.56 mln shares at $64.25, an 18.4% discount to stock's last sale on Mon
** Co intends to use net offering proceeds primarily to support its Beijing subsidiary to increase manufacturing capacity to produce indium phosphide substrates for export, for R&D, among other purposes
** Northland Capital Markets sole bookrunner
** AXTI has ~55.6 mln shares outstanding for $4.4 bln market cap at last close
** Through Mon, stock has surged nearly fivefold YTD and hit record intraday high of $83.25 on Fri
** 4 of 5 analysts rate the stock "strong buy" or "buy", 1 "hold"; median PT $28, per LSEG
(Lance Tupper is a Reuters market analyst. The views expressed are his own)
((lance.tupper@tr.com 1-646-279-6380))