Hilbert Transform - Trend vs. Cycle Mode (HT_TRENDMODE)
A binary indicator that determines if the market is currently in a trending state (1) or a cyclical state (0).
Visual Example

Synthetic ideal per library logic. Generated 2026-06-25 IST via docs/generate_all_previews.py (reproducible; maps to core Next<T> implementation).
Description
The Hilbert Transform - Trend vs. Cycle Mode (HT_TRENDMODE) indicator is a technical analysis tool that a binary indicator that determines if the market is currently in a trending state (1) or a cyclical state (0).
This indicator is primarily used for identifying key market conditions. It provides a robust signal that can be easily integrated into both simple strategies and more complex machine learning feature pipelines. Compared to its alternatives, it offers a distinct balance of responsiveness and stability.
Traders often combine this with other metrics to confirm signals and avoid false positives during sideways market regimes. It remains a standard tool for systematic trading models.
Use as a master filter for strategy selection. Deploy trend-following tools when TRENDMODE is 1, and mean-reversion tools when TRENDMODE is 0.
Determining the current market regime is the 'holy grail' of technical analysis. The HT_TRENDMODE indicator uses the rate of change of the dominant cycle phase to distinguish between trending and ranging price action, allowing traders to avoid 'whipsaws' in non-conducive environments. — Rocket Science for Traders
QuantWave implements this indicator via the universal Next<T> trait, guaranteeing bit-identical results between Rust streaming, Python streaming, and Polars batch (.ta() / map_batches) surfaces.
Formula / Specification
Implementation (quantwave-core/src/indicators/cycle.rs):
Gold-standard parity vectors: quantwave-core/tests/gold_standard/ht_trendmode.json.
Parameters
| Parameter | Default | Description |
|---|---|---|
| (none) | — | No tunable parameters for this detector. |
Usage Examples
Streaming (Rust)
use quantwave_core::indicators::HT_TRENDMODE;
use quantwave_core::traits::Next;
let mut ind = HT_TRENDMODE::new(14);
for price in &prices {
let value = ind.next(price);
}
Streaming (Python)
from quantwave import HT_TRENDMODE
ind = HT_TRENDMODE(14)
for price in prices:
value = ind.next(price)
Polars Batch (Python)
import polars as pl
df = (
pl.read_csv('ohlcv.csv')
.lazy()
.with_columns(
pl.col("close").ta.ht_trendmode(14).alias("hilbert_transform_trend_vs_cycle_mode_ht_trendmode")
)
.collect()
)
All surfaces are bit-identical via the single Next<T> implementation and proptests.
Edge Cases & Limitations
- Recursive DSP filters require a warm-up period; first N bars may be unstable or raw-pass-through.
- Designed for cyclic/mean-reverting regimes; trending markets can produce lag or drift.
- Parameter
period(or equivalent) controls cutoff — too small adds noise, too large adds lag. - Prefer chaining with other Ehlers tools (Roofing Filter, SuperSmoother) on noisy inputs.
- Validated via proptests against gold-standard vectors where available.
- No look-ahead bias; suitable for live streaming and batch feature pipelines.
Boundary Behavior
| Condition | Behavior |
|---|---|
| Warm-up | Leading bars return NaN until warmup_bars is satisfied. |
| period > len | When period exceeds series length, output is all NaN. |
| NaN inputs | NaN in input propagates to output (NaN out). |
| Invalid params | Non-positive period or missing required params raise ValueError. |
| Empty data | Empty input returns an empty result series. |
Related Indicators & See Also
Sources & References
Primary Source: https://www.tradingview.com/support/solutions/43000502014-hilbert-transform-trend-vs-cycle-mode-ht-trendmode/
Implementation: quantwave-core/src/indicators/cycle.rs (HT_TRENDMODE / HT_TRENDMODE_METADATA).
Parity: quantwave-core/tests/gold_standard/ht_trendmode.json
Provenance: Standards bulk upgrade 2026-06-25 IST — see docs/DOCUMENTATION_STANDARDS.md.