Better way to include multiple values in an if statement

Better way to include multiple values in an if statement

Using the following to execute a function based on the deal stage. Is there a better way to do this? I'm currently having to use && and input each deal stage I don't want to include. Is there some way to do like a if (deal.get("Stage") !- 'value','value2','value3'){
xyz
} ?

Sample code currently using:
if (deal.get("Stage") != 'Won' && deal.get("Stage") != 'Won - No Training' && deal.get("Stage") != 'Won - Pending Pay Processor' && deal.get("Stage") != 'Future Interest' && deal.get("Stage") != 'Nurturing' && deal.get("Stage") != 'Lost') {
    xyz
}