How do I dollar cost average when the shares are 500$/share and I'm only able to put in 300$?

The broker Interactive Brokers allows u to buy fractional shares which means u can buy a fraction of that share instead of 1 full share.

For example, if AMZN is $2000 and u only have $200 you can buy 0.1 shares of AMZN instead of having to save up to $2000 to buy 1 share.

u can DCA into that $500 stock depositing with $300 monthly using Interactive Brokers.​​​

Hi Justin, buying monthly is not Dollar Cost Averaging. It's just a regular investment. And you can't properly DCA individual securities as you can't buy fractional shares.

But semantics aside, instead of buying monthly, consider buying once every 3-6 months. As long as your trading cost is managed as well, and you can enter the market, it won't be an issue as long as you're still buying at a desired price.