Wedge pattern
A wedge is formed by two converging lines sloping the same way. A rising wedge leans bearish; a falling wedge leans bullish.
Unlike a triangle, both edges of a wedge rise together (rising wedge) or fall together (falling wedge), while drawing closer. Price keeps progressing, but less and less.
A rising wedge reflects a rally running out of breath: each new high is barely above the previous one. A break to the downside can announce a reversal or a correction. The falling wedge is the mirror image.
You see it both at the end of trends and as a correction within a trend. Combine it with an oscillator divergence and wait for a confirmed break.