Fibonacci Projection

A measured move from the last three confirmed pivots A-B-C: the A→B leg projected from C at the canonical ratios (61.8/100/161.8/261.8%) — the C→D target zone.

Quick reference

Item	Value
Family	Fibonacci
Input type	Candle (uses high, low)
Output type	FibProjectionOutput (4 prices)
Output range	projected from C in the A→B direction
Default parameters	none (swing threshold 5%, baked)
Warmup period	3 (three confirmed pivots)
Interpretation	C→D measured-move targets

Formula

last three confirmed pivots A, B, C:
  level(p) = C + p * (B - A)
for p in {0.618, 1.0, 1.618, 2.618}

level_1000 is the classic AB=CD measured move (the C→D leg equals A→B). See crates/wickra-core/src/indicators/fib_projection.rs.

Parameters

None. The swing threshold 0.05 is a baked-in family constant (pattern_swing.rs); the four ratios are fixed. FibProjection::new is infallible.

Inputs / Outputs

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

• Python. update((o,h,l,c,v,ts)) → (level_618, level_1000, level_1618, level_2618) or None; batch(high, low) → (n, 4) ndarray (NaN warmup).
• Node. update(high, low) → { level618, level1000, level1618, level2618 } 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 (A, B, C) are required; before that update returns None. Pinned by tests accessors_and_metadata and no_output_before_three_pivots.

Edge cases

• Measured move from three pivots is exact (test measured_move_from_three_pivots).
• reset clears all state (test reset_clears_state).
• Streaming equals batch (test batch_equals_streaming).

Examples

Rust

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

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // A=200 (high), B=160 (low), C=190 (high): A->B = -40, projected from C.
    let bars = [
        (199.8, 200.0, 199.8, 199.8),
        (160.0, 198.0, 160.0, 160.0), // confirms A @200
        (161.6, 190.0, 161.6, 161.6), // confirms B @160
        (171.0, 188.1, 171.0, 171.0), // confirms C @190 (projection ready)
    ];
    let mut fib = FibProjection::new();
    let mut last = None;
    for (ts, (o, h, l, c)) in bars.iter().enumerate() {
        last = fib.update(Candle::new(*o, *h, *l, *c, 1.0, ts as i64)?);
    }
    let v = last.unwrap();
    println!("{} {}", v.level_1000, v.level_1618); // 150 125.28
    Ok(())
}

Python

import wickra as ta

bars = [
    (199.8, 200.0, 199.8, 199.8, 1.0, 0),
    (160.0, 198.0, 160.0, 160.0, 1.0, 1),
    (161.6, 190.0, 161.6, 161.6, 1.0, 2),
    (171.0, 188.1, 171.0, 171.0, 1.0, 3),
]
fib = ta.FibProjection()
print([fib.update(b) for b in bars][-1])
# (165.28, 150.0, 125.28, 85.28)

Node

const wickra = require('wickra');
const fib = new wickra.FibProjection();
const bars = [[200.0, 199.8], [198.0, 160.0], [190.0, 161.6], [188.1, 171.0]];
let last = null;
for (const [h, l] of bars) last = fib.update(h, l);
console.log(last.level1000, last.level1618); // 150 125.28

Streaming

fib = ta.FibProjection()
for o, h, l, c, v, ts in candle_feed:
    proj = fib.update((o, h, l, c, v, ts))
    if proj is not None:
        abcd_target = proj[1]  # 100% — the AB=CD completion price

Interpretation

1. Measured move. After A→B→C, the projection answers "if D mirrors A→B, where does it land?" — the 100% level is the AB=CD target.
2. Three-point vs two-point. Unlike FibExtension, which extends a single leg, projection uses the A→B magnitude but anchors at C.

Common pitfalls

• Needs three pivots. Returns None longer than the two-point tools; on short histories it may never emit.
• Direction inherited from A→B. The projection continues the A→B sign from C; read targets relative to that direction.

References

• Carney, S. Harmonic Trading (2010); Fischer, R. Fibonacci Applications (1993).

See also

• FibExtension, FibRetracement, Abcd.
• Indicators-Overview — full taxonomy.