This plugin automatically looks for ticker symbols like (AAPL) or (GOOG) and link the tickers to research pages at InvestorGuide.com
“The plugin will not override existing links — e.g., if you already linked the ticker to another stock research page or your tag page. Moreoever, the plugin allows you to define acronyms and ticker symbols that should NOT be linked by the plugin.”
Info: http://www.investorguide.com/article/6100/stock-ticker-link-wordpress-plugin/
Download: http://wordpress.org/extend/plugins/investorguidecom-stock-ticker-link/