A truly effective trendline must meet two uncompromising conditions:

First, it must anchor to the trend’s “structural pivot points.” An uptrend line must precisely connect the consecutively higher lows (HL), while a downtrend line must strictly lock onto the progressively lower highs (LH)—these points are the true witnesses of trend momentum, not just incidental turning points within volatility.

Second, it must withstand repeated confirmation by key structures. When the price pulls back to the uptrend line and then makes a new high, or rebounds to test the downtrend line and quickly falls below the previous low—this intrinsic resonance with price action is the real sign that a trendline has practical significance.

If these two standards are met, the trendline becomes a reliable backbone throughout the market movement; otherwise, any arbitrary connection of points that ignores structural logic is merely a visual illusion on the chart and will ultimately fail amid real price fluctuations.

Essentially, the value of a trendline never lies in the skill of drawing lines, but in whether it helps us see the underlying order of the market: identifying the continuation and exhaustion of momentum, and capturing true trend reversals. Only by first understanding the structure will the trendline naturally emerge—this is the key leap in technical analysis from mere imitation of form to true grasp of essence.