[Rubinsalamander]

Roulette odds are 47,37% for doubling. So if you are not confident that your investment can beat that dont bother.

Otherwise use high leverage products in the stock market which will amplify your wins/losses. Best case would be to make a strategy write it down and stick to it. Your biggest Problem there is psychological strain if the 100K means a lot to you. You will at best have a miserable time and at worst panic sell in the wrong moment. So if you cant afford to lose most or all of the 100K dont invest it especially not in high risk products.

[matt_wulfeck]

I doubt most of the answers here will provide you with better probability than going to Vegas and putting $100k on black.

[Rubinsalamander]

Stock Market and Casino both have Fees/House Advantage.

The difference is that Casino is more or totally based on luck while there is a skill factor involved in the stock market. Also the stock market isnt a zero sun game because of economic growth

In the end Casino has nearly the same odds for everyone while in the stock market there is much more variance. But i would inclined to say that for most casino is the better option

[muzani]

Poker would give better odds I think.

[Rubinsalamander]

Depending on your skill, opponents and in some cases alcohol tolerance Poker would be a better and definetly more fun option.