Confirming support with trendlines, channels, and retracements

A three-tool vote

Editorial reading of this archive treats a support or resistance zone as a three-tool vote. A trendline, a parallel price-channel edge, and a Fibonacci retracement must land on the same price before that level is treated as a falsifiable hypothesis rather than a hunch about the trend.

The archive describes a support, resistance, or target zone as more reliable when separate techniques mark the same price. The walk-throughs show how those techniques are drawn and when they stacked.

How each tool marks a price

A trendline is a straight line through two or more swing lows or highs, extended forward and judged intact by whether closes stay on the trend side of the line. An uptrend line joins two or more lows and remains valid while closes stay above it. A downtrend line joins two or more highs and remains valid while closes stay below it.

A price-channel is a pair of parallel lines made by copying a trendline to the opposite swing so both edges can mark expected turning zones. After an initial steep uptrend line breaks, a flatter line can be copied to the opposite highs to form a parallel price channel, with turns expected when price reaches either channel edge.

A Fibonacci retracement is a set of percentage pullback levels measured between a swing high and a swing low. Those levels are used as candidate support or resistance that gain weight when they coincide with a trendline or a price-channel edge.

Horizontal support and resistance lines are placed through turning points or gaps. Those lines are static-levels. A close through the line is treated as a break, after which a former resistance can later act as support. That later use is role-reversal. A dynamic-level is a moving reference, such as a simple moving average, that travels with price and can act as support or resistance.

Four events in a turn

A bullish turn is framed as four events whose order can vary. Price reaches a downtrend support, a retracement, or a target. Price breaks upward through a downward channel or a flat range. A higher low appears. A higher high appears. The upward close through the channel or range is a channel-break.

A bearish turn is framed as four events whose order can vary. Price reaches an uptrend resistance, a retracement, or a target. Price breaks downward through an uptrend channel or range. A lower high appears. A lower low appears.

When separate techniques mark the same price

A support, resistance, or target zone is described as more reliable when separate techniques mark the same price. The GBPUSD walk-through stacked a trendline, a copied channel, and Fibonacci retracements including 23.6%, 38.2%, 50%, and 61.8%.

In the GBPUSD sequence, an April reaction supplied an uptrend line that was copied to the prior top to form a channel. The later rise reached the 50% retracement, a prior support flipped to resistance, and the upper channel boundary together.

In a 30-minute futures example, the first resistance in a topping sequence sat at the 38.2% Fibonacci retracement and at a 50-bar simple moving average.

Line adjustments and chart scale

A single trend is described as able to pass through three line adjustments. Price follows the line until a break. Acceleration forces a steeper line, often late in an advance. A moderate break with a slower pace forces a flatter line, often late in a decline.

Chart scale changes how many of those lines a stretch needs. Over the same EURUSD stretch from 12 December 2013 to 16 December 2013, a 10-pip range-bar chart allowed one downward trendline, while a 30-minute candlestick chart of that move required several successive lines.