We will each buy $500 worth of bitcoins and trade them for four years.
I don’t really understand you. Are you planning to invest in bitcoin for four years, or are you just planning to be trading? If you are planning to trade, then you shouldn’t start trading with $500. You can’t just jump into something you don’t really have much knowledge about. Trading is kind of risky, and it’s not something you can start with and expect profit instantly. Trading requires constant research, and you have to always put it into practice. So as a beginner, it’s just better to start with a small amount, but if you decide to start with all the $500, I won’t be surprised if you lose everything to trading.
$500 worth of bitcoins may not be much.
Why do you think $500 worth of bitcoin is not much? When investing, no amount is too small, you don’t have to invest which at the end you might end up being affected. If you know it's only $500 you can afford to lose, then it's better if you just invest the $500.
I checked your profile, and I noticed that you have been given a positive trust with the reference that you have used @albon escrow on Telegram to complete ETNY token transactions. I hope you are not investing the $500 in altcoins, and you are here claiming you are planning to invest it in bitcoin? If you invest in altcoins, you might end up regretting it. The coin that you are investing in hasn't been listed on exchange yet, you are just taking a great risk.