Ron Guth:
In 1853, the U.S. Mint reduced the weight of the Quarter Dollar to correct the ratio between gold and silver. The effect of the change was to make all previously-minted coins worth more than their face value. To denote the difference between the old and the new coins, the Mint added small arrowheads to the left and right sides of the date. Thus, it was no longer necessary to read the date on the coin to tell it if was old-tenor or new.
Before the change went into effect, the Philadelphia Mint struck over 44,000 of the 1853 No Arrows Quarter Dollar. As a result, this is a scarce date that is difficult to locate in Mint State. A small handful of MS64 to MS6 examples exist, and true Superb Gems are exceedingly rare. The example pictured above is one of only two PCGS MS67 examples certified so far.