Very superstitious, apparently. New evidence comes from a great study on the auction market for diamond rings.
Anne Bowers, associate professor of strategy at the University of Toronto, analyzed 1.5 million eBay listings of diamond solitaire engagement rings. Those rings that indicated a failed relationship (“right ring wrong guy”, “called off", "ended abruptly", etc.) sold less frequently, and for a lower price, than comparable rings that weren't "tainted."