Hi David,
Are you a Financial Advisor or A banker or some other type of investment financier? If not, I think it would be almost impossible for you to say, with a level of expertise that would make you an authority, there are No" risk free investments.
However, I will concede there is great risk if you are counting the Apocalypse caused by a world wide health Pandemic/epidemic, nuclear winter or the earth being destroyed by an Asteroid. Yes you are correct there is no guarantee. However, with regards to those events...having your money back won't make a difference.
You know David, one way to shut me up would be to give me the $10,000 and if within 12 months you don't receive $11,000. You can sue me and trash me all over the internet and run me out of custom knives.
EDIT: David I realize that $10K is a lot of money. My initial offer was a 10% return on $1,000. I'll even do it for $500.
So maybe along with you, you can get Giant, Bright Red, Brownshoe and one other to each put up $100 or $200.
Of course the other side of this is when you receive your check for the 10% return. Each of you will have to sing my praises here on BF.
HOLY COW, I just realized that you were right...even If you did receive the 10%...there would be risk involved.