A distribution (dividend and/or capital gain) is pending on this position. When a distribution is pending, the Change Since Close and Change Since Close % values are not displayed until all necessary adjustments have been made. If you have elected automatic reinvestment of shares, the Quantity and Most Recent Value fields will reflect the shares by the morning of the next market day.
For mutual funds, the Change Since Close values are restored when the fund prices at market close on the next business day.