** Shares of diagnostic test maker Exagen XGN.O down 16.8% post-market to $5.68 on equity offering news
** Vista, California-based co commences stock offering with Canaccord Genuity as sole bookrunner; deal size not disclosed
** It intends to use net proceeds for working capital, general purposes, and potentially acquire, in-license or invest in complementary technologies or business, per the SEC prospectus filing
** Co, which makes testing products that help in diagnosing auto-immune diseases such as rheumatism, has ~18 mln shares outstanding for ~$123 mln market cap
** Stock on Weds closed up 6.4% at $6.83, extending YTD gain to ~67%
(Lance Tupper is a Reuters market analyst. The views expressed are his own)
((lance.tupper@tr.com 1-646-279-6380))