I've been trying to work this for a while and I believe the odd one is the 4th figure, but don't seem to find a satisfying justification for this. Any help?
Few observations:
1) Bottom two dots seem to toggle left and right together.
2) Top items are doing a more complicated movement.
I'd go with the first. All the others have a bigger circle and a smaller dot together on one side of the "numerator".