Fibonacci Channel

A sloped base trendline through the two same-direction outer pivots, plus parallel lines offset by Fibonacci multiples of the channel width set by the opposite middle pivot.

Quick reference

Item	Value
Family	Fibonacci
Input type	Candle (uses high, low)
Output type	FibChannelOutput (base, level_618/1000/1618)
Output range	parallel channel lines at the current bar
Default parameters	none (swing threshold 5%, baked)
Warmup period	3 (three confirmed pivots)
Interpretation	Sloped channel support/resistance

Formula

last three pivots p0, p1, p2 (p0/p2 same direction, p1 opposite):
  slope     = (p2 - p0) / (bar2 - bar0)
  base(bar) = p0 + slope * (bar - bar0)
  width     = p1 - base(bar1)
  level(r)  = base(cur) + r * width
for r in {0.618, 1.0, 1.618}, cur = current bar index

level_1000 is the opposite channel boundary (through p1); the 61.8% and 161.8% lines sit inside and beyond it. The two same-direction pivots occur at distinct bars, so the slope is well-defined. See crates/wickra-core/src/indicators/fib_channel.rs.

Parameters

None. The swing threshold 0.05 is a baked-in family constant; the three ratios are fixed. FibChannel::new is infallible.

Inputs / Outputs

const _: fn(&mut wickra::FibChannel, wickra::Candle) -> Option<wickra::FibChannelOutput> =
    <wickra::FibChannel as wickra::Indicator>::update;

• Python. update((o,h,l,c,v,ts)) → (base, level_618, level_1000, level_1618) or None; batch(high, low) → (n, 4) ndarray (NaN warmup).
• Node. update(high, low) → { base, level618, level1000, level1618 } or null; batch(high, low) → flat number[] length n*4.
• WASM. update(high, low) → object (same camelCase keys) or null.

Warmup

warmup_period() == 3. Three confirmed pivots are required (two to slope the base, one for the width); before that update returns None. Pinned by tests accessors_and_metadata and no_output_before_three_pivots.

Edge cases

• Channel levels from three pivots are exact (test channel_levels_from_three_pivots).
• reset clears all state (test reset_clears_state).
• Streaming equals batch (test batch_equals_streaming).

Examples

Rust

use wickra::{Candle, FibChannel, Indicator};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Highs at (bar0, 200) and (bar3, 220); low (bar1, 100) sets the width.
    let bars = [
        (199.0, 200.0, 199.0, 199.0),
        (100.0, 190.0, 100.0, 100.0), // confirm high @200, low @100
        (108.0, 110.0, 108.0, 108.0), // confirm low @100
        (210.0, 220.0, 210.0, 210.0), // extend high to 220 (bar 3)
        (150.0, 200.0, 150.0, 150.0), // confirm high @220 -> three pivots
    ];
    let mut chan = FibChannel::new();
    let mut last = None;
    for (ts, (o, h, l, c)) in bars.iter().enumerate() {
        last = chan.update(Candle::new(*o, *h, *l, *c, 1.0, ts as i64)?);
    }
    let v = last.unwrap();
    println!("{:.3} {}", v.base, v.level_1000); // 226.667 120
    Ok(())
}

Python

import wickra as ta

bars = [
    (199.0, 200.0, 199.0, 199.0, 1.0, 0),
    (100.0, 190.0, 100.0, 100.0, 1.0, 1),
    (108.0, 110.0, 108.0, 108.0, 1.0, 2),
    (210.0, 220.0, 210.0, 210.0, 1.0, 3),
    (150.0, 200.0, 150.0, 150.0, 1.0, 4),
]
chan = ta.FibChannel()
print([chan.update(b) for b in bars][-1])
# (226.6666667, 160.7466667, 120.0, 54.08)

Node

const wickra = require('wickra');
const chan = new wickra.FibChannel();
const bars = [[200.0, 199.0], [190.0, 100.0], [110.0, 108.0],
              [220.0, 210.0], [200.0, 150.0]];
let last = null;
for (const [h, l] of bars) last = chan.update(h, l);
console.log(last.base.toFixed(3), last.level1000); // 226.667 120

Streaming

chan = ta.FibChannel()
for o, h, l, c, v, ts in candle_feed:
    lines = chan.update((o, h, l, c, v, ts))
    if lines is not None and c > lines[3]:
        pass  # price above the 161.8% channel line — strong breakout

Interpretation

1. Sloped band. The channel rides the trend's slope, unlike a flat support/resistance zone, so the boundaries adapt as the trend advances.
2. Width-scaled targets. The 61.8% / 161.8% lines extrapolate the established channel width as the next reaction levels.

Common pitfalls

• Needs a clean three-pivot structure. With erratic swings the base slope can be steep; read it together with the raw pivots.
• Re-anchors on new pivots. Each new confirmed pivot shifts the three-point window and can re-slope the channel.

References

• Fischer, R. Fibonacci Applications and Strategies for Traders (1993).

See also

• FibFan, FibArcs, LinRegChannel.
• Indicators-Overview — full taxonomy.