You have given way too little information .
If you want to design a fund, then you will have to do it. You can set up a token, as a side chain and dev out the code to use each token return to buy X percents of the X number of coins, not too hard, just a little bit of coding, and there is no reason to "platform" it out, you will be the only one that is touching it, so there is no need for anything but a wallet and that is more than enough for you to fail.