. the difference between those two prices is the spread.... you buy at the markets 'selling price' , we refer to it as their 'ask' ..... and you sell at their 'purchasing price' , we refer to it as their 'bid'..... forex charts are known as bid charts.... so it's the bid price that determines the high, low, open and close..... this can be confusing on high spread pairs.... as example, you might see the current gbpnzd bid, at 1.8050 but when you buy it your price might be 1.8080..... occasionally you'll see someone complain about a stoploss getting hit when the price came no where near it.... often this is due to the spread not being truly reflected in the chart...... you can keep the 'ask' line visiable on the chart for a better idea.....h