NewPriceLines

The Japanese "eight/ten new price lines" exhaustion count — count consecutive higher (or lower) closes warns the run is stretched.

Quick reference

Field	Value
Family	Candlestick Patterns
Input type	Candle (close)
Output type	f64 (signed signal)
Output range	{−1, 0, +1}
Default parameters	(count = 8) (Python)
Warmup period	2
Interpretation	−1 overbought (up-run exhausted); +1 oversold.

Formula

consecutive higher closes form "new price lines" up
consecutive lower  closes form "new price lines" down
signal = −1 once `count` consecutive higher closes
signal = +1 once `count` consecutive lower  closes
signal =  0 otherwise (and the moment a close breaks the streak)

Traditional Japanese practice flags eight new price lines (and a stronger ten/twelve) as exhaustion: the market has run one way so many bars in a row that a corrective pause is due. The signal persists while the streak stays at or above count and clears the instant a close breaks it. Source: crates/wickra-core/src/indicators/new_price_lines.rs.

Parameters

Name	Type	Default	Valid range	Source	Description
count	usize	8 (Python)	>= 2	new_price_lines.rs:55	Consecutive new closes that trigger the exhaustion signal. < 2 errors with Error::InvalidPeriod.

count() returns the threshold; streak() the current (up, down) run length; value returns the current signal if ready.

Signed ±1 encoding

+1.0 down-run exhaustion (buy warning), −1.0 up-run exhaustion (sell warning), 0.0 no signal (warmup emits None).

Inputs / Outputs

From crates/wickra-core/src/indicators/new_price_lines.rs:

use wickra::{Candle, Indicator, NewPriceLines};
// NewPriceLines: Input = Candle, Output = f64
const _: fn(&mut NewPriceLines, Candle) -> Option<f64> = <NewPriceLines as Indicator>::update;

A Candle in, an Option<f64> out. Python update(candle) / batch(close); Node update(close) / batch(close[]).

Warmup

warmup_period() == 2. One prior close is needed (first_bar_seeds_without_signal pins this).

Edge cases

• Eight higher closes → −1. (eight_higher_closes_signal_sell pins this).
• Eight lower closes → +1. (eight_lower_closes_signal_buy pins this).
• Break clears. A counter-close clears the signal and starts the opposite streak (break_in_streak_clears_signal pins this).
• Unchanged close resets. An equal close zeroes both streaks (unchanged_close_resets_streak pins this).
• Finiteness. Candle::new rejects non-finite fields, so no in-method guard is needed.
• Reset. n.reset() clears the prior close, both streaks and the last value (reset_clears_state).

Examples

Rust

use wickra::{BatchExt, Candle, Indicator, NewPriceLines};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut n = NewPriceLines::new(8)?;
    let candles: Vec<Candle> = (0..12)
        .map(|i| { let cl = 100.0 + f64::from(i); Candle::new(cl, cl, cl, cl, 1_000.0, 0).unwrap() })
        .collect();
    println!("{:?}", n.batch(&candles).last().unwrap()); // Some(-1.0)
    Ok(())
}

Output:

Some(-1.0)

Python

import numpy as np
import wickra as ta

n = ta.NewPriceLines(8)
close = np.arange(12, dtype=float) + 100
print(n.batch(close)[-1])  # -1.0

Node

const ta = require('wickra');
const n = new ta.NewPriceLines(8);
console.log(n.batch(Array.from({length: 12}, (_, i) => 100 + i)).at(-1)); // -1

Streaming

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

let mut n = NewPriceLines::new(8).unwrap();
let feed: Vec<Candle> = Vec::new(); // your live stream
for candle in feed {
    match n.update(candle) {
        Some(-1.0) => println!("up-run exhausted"),
        Some(1.0)  => println!("down-run exhausted"),
        _ => {}
    }
}

Streaming update and batch are equivalent tick-for-tick (batch_equals_streaming pins this).

Interpretation

1. Exhaustion warning. Eight-plus straight closes one way flags a stretched move; tighten stops or fade with confirmation.
2. Strength tiers. Ten or twelve lines is a stronger warning than eight; run multiple instances for a ladder.
3. Not a top/bottom caller. It says "due for a pause", not "reverse now" — use with price structure.

Common pitfalls

• Trends overrun it. Strong trends can print many more than eight lines; do not blindly counter-trade the first signal.
• Close-only. It counts closes, ignoring intrabar action.
• Equal closes reset. A flat close breaks the streak — expected on low-tick data.

References

A classic Japanese candlestick concept ("shinne" / new price); see Nison, S. (1994), Beyond Candlesticks.

See also

• Indicator-TdSetup — the DeMark consecutive-close count.
• Indicator-Rsi — overbought/oversold by momentum.
• Indicators-Overview — the full taxonomy.