A rounding top may form at the end of an extended upward trend and indicates a reversal in the long-term price movement. The pattern can develop over several weeks, months or even years, and is considered a rare occurrence by many traders.
A rounding top represents a sell signal to technical analysts. The initial upwards trend becomes exhausted as the demand for the stock dries up. The reversal to the downward slope of the rounding top indicates that demand has tapered off and a surplus supply is present, basically there are more sellers than buyers. A rounding top represents a bearish take on the stock.