Whose trades would you like to see?
After you've configured your widget the way you like it, copy the code above into your site's template. Hints:
Wordpress: from the Wordpress dashboard, go to Appearance/Widgets, add a new "text" widget, and paste the above code into the widget. Note that this widget will unfortunately not work on blogs hosted on wordpress.com.
Tumblr: customize your template, and insert the above code into the template HTML in the location you would like it.