The topic of rising wedges in a price chart came up recently. A rising wedge on declining volume will often break sharply. (If it doesn't finish with a blowoff top)
And the pattern is fairly reliable in different timeframes.
Conversely, a declining wedge on declining volume will often rally sharply, as the selling dries up.
Of course no price is fail-safe. Always protect yourself. That is what trading is. Expecting the unexpected while trading the expected.