Lower High
A rally peak that fails to reach the prior swing high — the second structural requirement of a defined downtrend.
A lower high forms when a relief rally fades before taking out the prior peak. It signals that sellers are willing to distribute at progressively lower prices — buyers lack the conviction to push through prior resistance. Combined with lower lows, it defines a downtrend.
In a declining market, the first significant lower high after a long uptrend is often the earliest warning that the uptrend is in trouble — before a lower low has even formed.