Gold Price - simple, nicely designed commodities price chart.
Just place the shortcode into a text widget. If that doesn't work (it just renders [gold-price] in text) then that means your theme isn't 'widgetized' which you can fix easily by adding 1 tiny piece of code to your theme functions.php:
Add this code above to fuctions.php between the tags. A good place would be either at the very top or the very bottom of the file. Once you've done this you should be able to use shortcode in widgets now.
The markets are closed on weekends and public holidays, so the prices will stay the same untill the market opens again and the feeds are updated.
This plugin pulls XML data feeds from dgcsc.org The price data is surprisingly accurate although obviously we offer no guarantee. Remember "live market prices" can be extremely volatile, meaning prices can change very rapidly over a short period of time. For example, the gold price may spike up 5 dollars, then return to where it was in a matter of seconds. Our feed is only updated every 15 mins, so if there's a sudden change in price or a spike then that move could be missed completely. Likewise the price may be fetched right at the top of the spike. So keep in mind that what you're seeing is a "snapshot" of the price at a particular instant in time.
You can do some basic presentation adjustments via Gold Price > Settings. Beyond this, you can completely customise the design in the custom CSS box
If you've tried all the obvious stuff and it's still not working please request support via the forum.