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Investment banks and many, many, many people who are finance professionals got destroyed by the stock market downturn.
So why are you beating yourself up for not predicting it? How are you supposed to know better than everyone else?
Do you think you're God or something? Why does your husband expect you to predict the unpredictable?
At your age, putting all your retirement $ in CDs has always been a super stupid approach, on a level with stuffing it into coffee cans and burying it in the garden. Your DH's approach is wrong, even though short term it looks smart.
But retirement involves long term investing---25 years, in your case! The stock market will (of course) rebound, if only for the reason that all the politicians have their own wealth based on it. You can bet your sweet life that they will continue passing regulations and bailing companies out until it goes up again.
It's your decision whether or not to tell your husband how much you've lost (although I have to point out that of course you have no real losses because you haven't had to sell yet).
I'd vote for telling your DH though---his reaction will teach you a lot about the longevity of your relationship, so at least you'll have gained some information that may be of use.