The DOMMouseScroll function in your JavaScript sets originalEvent.wheelData to originalEvent.detail multiplied by 60 on Firefox, but it should actually multiply it by negative 60.
Other than that, your chart looks nice and works pretty well.
If you only ever used Firefox, you wouldn't know the difference
I know there are scrolling problems, especially on Mac with the trackpad. If anyone wants to donate a Mac for testing, feel free. I don't have one, so it could take some time to get this worked out.
I won't add MACD to this site. It is available on RTBTC.