this is one of the sites.
if you see the graph it is the price of a bitcoin as it fluctuates during the day.
Bitcoin Price Index - Real-time Bitcoin Price Charts
you can change it to week month all to see previous prices.
Price can be very volatile to avoid this if you want to take some risk out buy bitcoins as you need them and speand just as fast which usually takes a minimum of a few days. or you can have them in different wallets that are cash.
There is a fee when you sell 1% which is small compared to WU or MG....
Another plus is it is instant once you decide to send Bits the person gets it in there account the second you press send... transaction done.....
Peace