Bit late on this, but I'd look in spreading it across someone else's trading portfolio. This comes with a lot more reward and a lot less risk (still some risk) as because the funds are press across various companies if one goes down chances are it'll easily be countered by the others that will likely be on the up. But again, still risky...
Or alternatively I have $20,000,000 in water damaged notes that you're welcome to have, I'll need a small refundable transfer fee... Say £20,000 for insurance purposes..