Fingerprint ID Firm Cogent Soars in Debut  NEW YORK (Reuters) - Shares of Cogent Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=COGT.O target=/stocks/quickinfo/fullquote"&gt;COGT.O&lt;/A&gt; soared  50 percent in their market debut on Friday after the  fingerprint identification company's initial public offering  priced at the top end of its range.