Stocks Lower as JP Morgan Weighs on Dow  NEW YORK (Reuters) - U.S. stocks opened lower on Wednesday,  with weaker-than-expected earnings from J.P. Morgan Chase   Co.  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=JPM.N target=/stocks/quickinfo/fullquote"&gt;JPM.N&lt;/A&gt;, and an investigation into the insurance industry among  the factors weighing on Wall Street.