(since the price is continuing to plunge) My wife thought its a waste of money and a bad investment - "See! I told you, you didnt listen to me!" Im gonna be stubborn and still HLOD! My gut feeling its gonna spike in few months and hopefully, my wife is WRONG and start smiling when she sees the price going up and strong! 
Buy her a book on investments. Tell her not to nag about it until she finished the book. There is no way you can get through to her. Just like you telling her she doesn't need new pairs of shoes.