The NAV of the direct plan will always be higher as they give extra returns than regular ones. This happens because the regular plan of the mutual fund has a higher expense ratio as the commission of the distributor will always be included in the TER (Total Expense Ratio), The portfolio of both regular and direct plans will be same but when seeing returns you will notice that the direct plans will give a slightly higher return and due to this reason the NAV of the direct plan will be higher as the return is higher and the NAV of regular plan will be lower as the returns are slightly lower. In my opinion you should look at the performance of the fund and avoid looking at the amount of units. The Mutual Fund units do not act like a stock and they are fundamentally different from it.