Rises quickly, falls slowly, is a sign of accumulation
If the price of the coin is rising very quickly but falling very slowly, it basically means that large funds are quietly collecting more coins in preparation for another wave of increase later.
Falls quickly, rises slowly, is a sign of distribution
If the price of the coin suddenly falls very quickly but rebounds very slowly, it may indicate that the operators are quietly selling off their coins, and the market may be entering a downward trend.