The reason for the drop is because of something called Capital Gain Distribution. A capital gain distribution is a payment to investment company shareholders of profits realized on the sale of its securities. Equity funds usually pay out these amounts once a year, typically in December. In general, capital gains distributions reduce the value of the fund, but as a share holder, if reinvested, you’ll have more shares. Also these distributions are taxable income for the recipient, so funds that allow reinvestment instead of distribution are sometimes preferred by investors in high tax brackets.