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You are worrying unnecessarily. Get your husband a copy of the Economist's Guide to Investment Strategy book and tell him the downfall.
I made the same mistake myself. I saved 75% in state investments (government bonds) and rest in 100% stock market investments (through mutual funds).
The market crash wiped me clean. I don't regret it.
Risk is inherent in any investment. The degree of acceptable risk over return is what makes an investment.
In 2006 i made an excel sheet and found out that More Risk does not mean more return. Neither does less return means less return.
I was calculating returns on Mutual Funds of a large bank (long term) versus the bank's own FDs and CDs and Gilt edge funds.
In a period of 1-2 years, investing in CDs and Gilt edge funds actually brought MORE returns than a riskier investment. (this was just before the crash: i should have understood the meaning). I switched more from stock market to these funds and had left only 25% in stock market when it crashed.
Do a research and read the book. Its very good.