Arc Radius Trend [JOAT]Arc Radius Trend
Introduction
Arc Radius Trend is an open-source, overlay-based trend-following system that replaces the static ATR band of conventional supertrend-style indicators with a curved, acceleration-responsive radius. The band does not scale linearly with volatility alone — it also responds to how fast price is accelerating or decelerating, expanding when momentum surges and tightening when price action becomes uniform. This gives it a shape that mirrors how institutional participants view momentum: not as a constant envelope, but as one that breathes with the market.
The problem ART solves is over-sensitivity. Standard ATR-based trailing stops flip direction too freely during acceleration events, producing false exits at exactly the moment when the trend is strongest. By expanding the radius during acceleration, ART gives trends room to breathe without permanently widening the band for all conditions.
Core Concepts
1. Velocity and Acceleration from Price
ART computes price velocity as the EMA of the bar-to-bar change in close, and acceleration as the EMA of the change in velocity. Both use the same smoothing length. Acceleration is normalized by ATR so that it is dimensionless and comparable across instruments and timeframes:
velocity = ta.ema(ta.change(close), accelLength)
accel = ta.ema(ta.change(velocity), accelLength)
accelNorm = atr > 0 ? accel / atr : 0.0
2. Curved Radius Scaling
The base radius is ATR multiplied by a configurable multiplier. The acceleration norm is then used to scale that radius with a power function, creating a nonlinear expansion curve. The exponent (Curve Strength) controls how aggressively acceleration widens the band:
radiusScale = math.pow(1.0 + math.min(math.abs(accelNorm), 2.0), curvePower)
radius = atr * baseMult * radiusScale
3. Ratcheting Band Logic
The active band ratchets in the direction of the current trend. When price is above the band (bull), the lower band is preserved at its maximum achieved value, preventing it from retreating while the trend holds. The trend flips when price closes through the opposite band:
trend := close > upperBand ? 1 : close < lowerBand ? -1 : nz(trend , 1)
activeBand = trend == 1 ? lowerBand : upperBand
4. JOAT Institutional Expansion Layer
Each JOAT indicator carries a shared Expansion Layer — an adaptive spine built from price efficiency, Shannon entropy, Parkinson range volatility, and a market impact ratio. The spine tracks the dominant flow using an KAMA-style adaptive constant, and its width is scaled by ATR ratio, range volatility, and noise. Stress and calm rails extend beyond the outer context boundary and change color based on composite stress readings. Bull and bear regime shift nodes mark confirmed directional transitions in the expansion layer state.
Features
Curved radius expansion: Band width nonlinearly expands during price acceleration events
Ratcheting trend band: Lower band preserved on bull trend, upper band preserved on bear trend — no backward drift
Outer envelope: A second ring outside the active band provides an extended volatility reference
Trend-state candle coloring: Candles tinted to reflect current trend direction
Regime flip nodes: Circle markers on the active band at confirmed bull and bear regime transitions
JOAT Expansion Layer: Adaptive spine with efficiency/entropy scoring, context box, stress rails, calm rails, and shift nodes
Stress and calm telemetry rails: Outer halos that widen with impact ratio and volatility stress
Dashboard (top right): Live display of trend state, active band level, normalized acceleration, and last flip
All signals on confirmed bars: No repainting — all state changes fire only on barstate.isconfirmed
Input Parameters
Radius Model:
Radius ATR Length: ATR period for radius computation (default: 21)
Base Radius Multiplier: Baseline band width in ATR units (default: 2.4)
Acceleration Smoothing: EMA length for velocity and acceleration (default: 8)
Curve Strength: Power applied to acceleration scale — higher values expand the band more aggressively (default: 1.35)
Outer Envelope: Multiplier for the secondary outer ring (default: 1.65)
Display:
Trend-State Candles toggle
Show Dashboard toggle
JOAT Expansion Layer:
Efficiency, Entropy, Impact lengths; Adaptive Fast/Slow periods; Context Width
Spine, Context Box, Regime Nodes, Candle Tint, Projection Bars, and Opacity toggles
Independently configurable Bull, Bear, Neutral, and Accent colors
How to Use This Indicator
Step 1: Establish trend direction
Read the active band color and the dashboard. Green indicates bull trend; red indicates bear. Use this as the primary directional filter for entries.
Step 2: Watch for confirmed flip nodes
Circle markers at confirmed trend reversals mark the bar where the band direction changed. These are not entry signals — they are context anchors. Evaluate what triggered the flip (structural break, momentum loss) before acting.
Step 3: Use the outer envelope as a volatility reference
When price extends to the outer envelope, the market is in elevated acceleration. This is not necessarily a reversal signal — it may indicate trend continuation with excess momentum.
Step 4: Read the Expansion Layer spine
The JOAT spine color and state convey institutional flow independent of the ART band. Bull spine with bull ART band is high-confidence alignment. Divergence between the two (e.g., bull ART, neutral spine) suggests weakening conditions.
Indicator Limitations
Acceleration-driven radius expansion may produce very wide bands during high-velocity events, temporarily reducing the band's usefulness as a stop reference
The ratchet mechanism preserves the band in the trend direction — during prolonged consolidation, the band will not tighten until a directional break occurs
On very low-liquidity instruments, the ATR-based radius may be structurally noisy; increasing the ATR length reduces this
Arc Radius Trend does not generate entries. It identifies directional state and provides a trailing reference level
Originality Statement
Arc Radius Trend is original in its use of normalized price acceleration as a multiplicative, power-scaled modifier to ATR radius. Existing supertrend variants use static ATR multiples or linear volatility adjustments. The combination of:
Velocity → acceleration derivation applied to a curved radius (not a flat multiplier)
Power-function scaling that produces nonlinear radius expansion only during acceleration events
Ratcheting band logic that is conditioned on the curved radius (not a fixed channel)
An institutional expansion layer carrying efficiency, entropy, Parkinson range vol, and impact scoring as a second independent context layer
...makes ART a structurally distinct contribution rather than a parameter variation of existing published work.
Disclaimer
This indicator is provided for educational and informational purposes only. It is not financial advice or a recommendation to buy or sell any instrument. Trading involves substantial risk of loss. Past behavior of this indicator does not guarantee future results. All signals should be validated within a complete trading framework that includes risk management. The author is not responsible for trading losses resulting from the use of this indicator.
-Made with passion by jackofalltrades
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