This may not seem like much, but if you can manage to put away an extra $10 per day at 10% over 40 years, you’re talking about having $1.6+ million! People aren’t trained to think like that, and our education system certainly doesn’t seem to be giving them these tools. You cannot attempt to put aside huge sums – fortunes are built $1 or $3 at a time

Its a lot of stocks out there that you can invest into under 100bucks but you must conduct the research. You can also go to www.treasurydirect.gov and obtain an I-Savings bond account and continue to add to that until you have enough for a ROTH IRA from T-Rowe price, fidelity or vanguard. Also the feds are going to release myRA(Retirement account) later this year for people with low income or small capital. Keep this within mind

Best of Luck.. Take Care

You are seriously going to get ripped off if you're thinking of stocks and shares.

Rigal has suggested buying something you can sell on ebay. You obviously have to shop around so you maximise your profits, coz Ebay take a rip-off commission for using their services, straight away. I really don't think you're going to start much of any sort of a business idea with $50 or $100, tbh.

Probably best to save your money until you have something sensible like $1000.

You can go for stock trading with this amount there are many stocks out there that you can invest into under but you must do a little bit of research.

Retirement

Something you can sell on ebay for $100 or $200.

subscribe to the wall street journal and read it for a couple of hours every day. the education you have "invested" in will be invaluable.

save five hundred to a thousand dollars, then invest it in a no load mutual fund.

Buy ETFs that pay monthly distribution

Put it in the bank.

Save up more.