Shares of Lyntris moved lower in their trading debut Wednesday after the defense-technology company's downsized initial public offering was priced at $17.50 a share, below the expected range of $19 to $21.

Lyntris shares were recently changing hands at $15.83, down 9.5%, after opening at $15.50, well below the IPO price.

The offering of 17 million shares included 5.71 million shares sold by Lyntris and nearly 11.3 million shares sold by investors in the Falls Church, Va., company.

Lyntris had previously set the size of the IPO at 24 million shares, with the company offering 4.88 million shares and shareholders selling 19.1 million shares.