After a head and shoulders pattern is completed, the typical price action reverses the prior trend. This pattern is a classic technical analysis formation that signals a shift from bullish to bearish momentum. Traders expect a downward movement once the price breaks below the neckline, which acts as a key support level.

The initial move is often swift as the breakout triggers stop-loss orders and initiates fresh short positions. The distance of the expected decline is typically measured from the highest point of the "head" to the neckline, projected downward from the breakout point.

Volume plays a critical role in confirming the price action. The breakout should be accompanied by increased volume, signifying strong selling pressure. If the volume is low, the breakout may lack conviction, increasing the risk of a false signal.

After the breakout, it’s common for the price to retest the neckline, now acting as resistance. If the retest holds and the price resumes its decline, it strengthens the bearish outlook.

Traders often use this pattern in conjunction with other technical tools, such as moving averages and momentum indicators, to confirm the reversal and identify potential profit targets. However, like all patterns, its success rate varies across markets and timeframes.