I have 500$ how to double the amount in one week?

Open a stock trading account.

Sell a put option on CMCSA with a strike price at 55.00 expiring on Feb 14 for 0.78 per contract.

At the same time buy a put option on CMCSA with a strike price at 54.50 expiring on Feb 14 for 0.52 per contract.

Each contract will net you $26 and will open you up to $50 of risk ( meaning a net loss of $24 per contract if CMCSA ends on Feb 14th under $54.50 )

Sell and buy 20 contracts. This will instantly net you $520 which will immediately double your money waiting is for schmucks.

Then just hang onto those contract until they expire on Feb 14th If they expire with CMCSA over 55.00 congratulations you just doubled your money. If they end under 54.50 you lose all your money.

I am not saying its a good Idea. I am just saying it will double your money.

Hold onto your $500. Work and earn $500. Don't spend it.

It sounds trite but at the level of money you are talking about doing valuable things and having people throw money at you is screamingly obvious.

If you do not have the skills to generate $500 from your efforts, then you have identified an underlying condition that cannot be solved by, e.g., gambling.

Gamble it. Stock futures, state lotteries, or casino table games.

Don't just double it. Triple it.

Post a bid for a contract on Freelancer or oDesk and then turn around and outsource the job on an hourly basis.

Get a $1000 contract and farm the work out for $500

Pokerbot - Grind it out! https://github.com/mdp/JsPoker

I doubt anything legal will return that fast without you putting $500 worth of sweat into it. Good point forgot about gambling.

Get a job?

put your money down on the side walk then when someone goes to pick it up, mug them.

legal way ?

illegal way ?