Page load time, along with not being able to handle peak server load (high usage periods such as mid US Election) are the two biggest issues with this website.
You are dealing with a market where real cash is being used in trades, you need to deliver a high standard of performance to your customers. This means that traders need to have reliable and consistent access to the market to make timely trades when new information comes to light. Currently this is substandard.
I have run a page load time test on pingdom.com (Dallas, Texas, USA based server) and it has returned a result of 6.94s, uptrends.com (from an Auckland based server) returned 4.00s. So most of your customers will be between these two extremes.
For a website such as this, it should take no longer than 2.00s to load a page. Further, you need to work closely with your hosting provider to accomodate for those peak usage periods (more CPU time, bandwidth etc).