I don't think the city stopped honoring anything or changed any rules. The medallion buyers were just speculating and didn't see the future well. No different from people who buy property for retirement then there's a recession and the surrounding population declines and it becomes worthless. Investment is gambling. Everyone knows that. You're supposed to diversify. Humble wage earners don't have that problem. Drivers who rent medallions don't have that problem. Only the risk taking ones who took loans for something that might lose value do.