Work.
That would have been my 1-word answer, but the site tells me it's too short.
Yes, you could invest your money in the hopes of getting a higher return; and it might work. But any investment entails the risk of loss. And that risk is highest early on when a person is less experienced and doesn't know where to invest.
I wouldn't want you to lose your hard-earned money or have a bad experience at 16 that sours you on taking risks. Realistically, the way to add to your stash without any chance of losing it ... involves finding paid work.
Local jobs for 16-year-olds won't pay a lot. But online you're ageless. If you learn a skill such as web design, video editing, or programming, then you could earn more per hour and freelance as much as you like.
Finish high school first. Never burn bridges and at this time you wouldn't want to do that with your parents. But in the mean time find a niche in a space and devote 100% of your extra energy to it. When I was 15 I had just finished rewiring my entire high school's ethernet system. I brought on 5 other kids my age during the summer and we had guidance from some older staff who showed us the ropes and let us go and do whatever we had to, to get the project done.
Throughout the whole process I learned to ask question and not be afraid to try and fail. My point to telling you this is that with $500 you've got very little to lose. You can always deliver pizzas and make that back in a few weeks. So don't be afraid to try something really crazy to get you somewhere. Also remember to ask for help, advice and be HUMBLE.
Read about starting businesses online, I would say read some books, but with such a limited budget you're better off saving your money for your business. Don't forget to take notes! It helps retain the information you read.
Invest. Grab a copy of Tony Robbins' new book Money Master the Game to begin learning that world.
Iterate. How did you make the $500? Assuming you earned it in some business-like way, find a way to repeat that and find a way to provide that service at a larger scale.
Learn. Read. A lot. The books you read now will dramatically impact the rest of your life.
Intention. I like the perspective of money as energy, and energy needs direction. Know what is important to you (which will change over time) and where you want to focus your energy (financial, emotional, physical, etc.)
Service. Another perspective I like is money as feedback for how much value you are creating in the world. See Wealth Warrior by Steve Chandler for more on that.
Congrats on an excellent start to becoming an entrepreneur! Being here (on Clarity) and jumping in and asking a question (versus just lurking) is a great sign that you are willing to take action.
Here are some of my initial observations and suggestions...
1. Begin with letting go of any assumptions or hangups you may have (or may think other people have) about your age.
2. Consider that the money is only one of your resources. Now write down all of your OTHER resources before you start putting a plan together.
3. Answer these questions (for yourself AND the next time you post a question try to be more clear):
What does "realistically" mean? And in what time frame? And how much risk are you willing to take? And increase by how much?
The best advice I can give (though unsolicited) is this:
When asking a question - make sure you are very clear about what you want AND make sure you are providing sufficient information about your goals and situation.
Best of luck to you!
Invest your money on some good books. Knowledge will take you closer to wisdom, and wisdom is knowing that it takes knowledge to achieve your dream.
Realistically speaking, there's no shortcut to grow $500 to $500,000 or something more.
Get trained on developing mobile apps.
I hired a young man, like you, to build a mobile app for me. He was smart, tenacious, creative and he made almost $3,000 for his first app out of the box that he did in his spare time.
At 17, people thought I was nuts to hire him but...he had character, integrity and drive.
I love this question. First of all don't disregard any information any other expert has given you, all of their answers will help you. However, if you really want to grow your $500 quickly, eliminate all of your assumptions about money. I hate to break it to you but $500 is almost nothing investment-wise.
So what you're really asking is how can I make money from nothing? Realistically, getting a job (which you should do for sustainability purposes) is not a tangible way to generate a substantial amount of income at 16. Investing your money may lead to substantial amounts over a long period of time (at least 5+ years assuming your investment was well researched). If you want to create capital from nothing you need to develop a skill or realize opportunity where most people don't.
I would suggest reading this article on how entrepreneur students create large amounts of capitol on only $5.
https://www.psychologytoday.com/blog/creativityrulz/200908/the-5-challenge
So to answer your question: If you want to create money from nothing you need to begin to think like an entrepreneur and realize opportunity where others may have not.
Explore your interests as deeply as you can before any life situations or institutions re-focus you on things you'll find less interesting. As stated above, a primary avenue for exploring those interests should be work.
Open an IRA and invest most of it. And keep the rest to spend or stash away for when you really want to buy something.