$870 is a really specific figure, as though it's your whole bank account. Keep it liquid (cash or something easily and quickly exchanged for cash) in case of emergency if you're not sure what to use it for.<p>Note that an emergency may not necessarily be an extensional crisis; an emergency can simply be a need to take advantage of an opportunity.
Money isn't worth anything right now (beyond its face value) because we have extremely low interest rates at this time. I would suggest using it to buy some stocks in a sector you have some understanding about. If it goes well, you will know a place you can put money in the future. (This only is feasible if you can afford to lose your $870 if it doesn't go well.)<p>Also, if you have any debt at all (school loans, etc.) you can probably make a better percentage profit paying your debt off early than you can in any other way.
Get a cheap thinkpad off of ebay (t4xx/t5xx) and put linux on it, use the rest for buying textbooks, pen/paper and what you don't spend on that save for emergencies/get health insurance. Then learn how to program, python is a good start with MIT 6.0x classes.
I think it depends on where your knowledge lies.<p>If you have the know-how, you can probably make a bit off sports betting, or stock investments, but otherwise high interest savings or a managed fund / superannuation would probably be best.
By defining what "best" means first.<p>Higher return? Lower risk? Long or short term?
You can buy a lot of books with that and it could be (if you read it) the "best" investment.
pick up some venezuelan government bonds. they are trading at about 85 cents on the dollar currently so you should be able to pick up one. the return is about 13% annually (haven't checked in a couple weeks). They're backed by black gold so you're set.