should doog add a fee to encourage long term investing and maintain a consistent bankroll?
perhaps a fee when you invest that is returned after a certain time?
IMO: No. One of the big advantages of investing in JD is that it's incredibly liquid. You can pull out your money at will (assuming you stay below the size of the hot wallet) and you'll never incur a cost for liquidating your investment. If you invest in a bond/loan on an exchange, you lose the spread and the exchange fee if you want to get your money out quickly. If you add a fee that is only returned after some time, you discourage using JD as a money-parking location.