DoubleTap

DoubleTap is a built-in TypeScript strategy from @tradejs/strategy-double-tap.

It detects double-bottom and double-top structures, then trades the breakout/breakdown with stop and target prices produced by the pattern engine.

Visual overview

The illustrations are schematic, not market data. Exact thresholds, confirmation rules, and risk parameters come from the active strategy config.

Entry Logic

1. Replays candles through createDoubleTapEngine(...).
2. Reads runtimeState.pattern.
3. Skips until a pattern exists.
4. Uses LONG config for a long pattern and SHORT config for a short pattern.
5. Computes riskDistance from current price to pattern.stopLossPrice.
6. Computes riskRatio from target distance divided by risk distance.
7. Sizes quantity from MAX_LOSS_VALUE / riskDistance, using the RISK_FEE_RATE, RISK_SLIPPAGE_BPS, and RISK_MARKET_IMPACT_BPS estimates.
8. Returns entry with double-tap figures and doubleTapContext.

Entry codes:

• DOUBLETAP_DOUBLE_BOTTOM_BREAKOUT
• DOUBLETAP_DOUBLE_TOP_BREAKDOWN

Exits

When a position exists:

• DOUBLETAP_OPPOSITE_PATTERN_EXIT when DOUBLETAP_EXIT_ON_OPPOSITE_PATTERN=true and the engine detects the opposite pattern.
• otherwise POSITION_EXISTS.

Configuration keys

The keys are grouped by purpose. Common runtime, AI, ML, shared indicator, and position-sizing keys keep the same meaning across the built-in strategies.

Group	Keys	Purpose
Runtime and decision services	ENV, INTERVAL, MAKE_ORDERS, CLOSE_OPPOSITE_POSITIONS, BACKTEST_PRICE_MODE, AI_ENABLED, AI_MODE, MIN_AI_QUALITY, ML_ENABLED, ML_THRESHOLD	Select the runtime mode and candle interval, control order placement, and enable optional AI or ML decisions.
Shared indicators	MA_FAST, MA_MEDIUM, MA_SLOW, OBV_SMA, ATR, ATR_PCT_SHORT, ATR_PCT_LONG, BB, BB_STD, MACD_FAST, MACD_SLOW, MACD_SIGNAL	Set the periods used to build shared market context and signal filters.
Pattern geometry	DOUBLETAP_PIVOT_LENGTH, DOUBLETAP_PIVOT_TOLERANCE_PCT, DOUBLETAP_MIN_PATTERN_HEIGHT_PCT, DOUBLETAP_MIN_PATTERN_HEIGHT_ATR, DOUBLETAP_ATR_PERIOD, DOUBLETAP_MIN_TAP_SPACING_BARS, DOUBLETAP_MAX_PATTERN_AGE_BARS, DOUBLETAP_MIN_LEG_SYMMETRY_RATIO	Define pivot confirmation, tap similarity, minimum height, spacing, age, and leg symmetry.
Breakout quality	DOUBLETAP_MIN_BREAKOUT_DISTANCE_ATR, DOUBLETAP_MAX_BREAKOUT_DISTANCE_HEIGHT_RATIO, DOUBLETAP_MAX_BREAKOUT_DISTANCE_PCT, DOUBLETAP_MAX_BB_WIDTH_PCT, DOUBLETAP_MAX_BB_WIDTH_PCT_LONG, DOUBLETAP_MAX_BB_WIDTH_PCT_SHORT	Limit breakout distance and Bollinger width, with directional volatility overrides.
Entry timing	DOUBLETAP_ENTRY_MODE, DOUBLETAP_CONFIRMATION_MAX_BARS, DOUBLETAP_MAX_ENTRY_CONFIRMATION_BARS, DOUBLETAP_MAX_ENTRY_CONFIRMATION_BARS_LONG, DOUBLETAP_MAX_ENTRY_CONFIRMATION_BARS_SHORT, DOUBLETAP_RETEST_MAX_BARS, DOUBLETAP_RETEST_TOLERANCE_ATR	Choose the entry mode and bound confirmation and retest timing, with directional confirmation overrides.
Target, stop, and exit	DOUBLETAP_TARGET_FIB_PCT, DOUBLETAP_STOP_FIB_PCT, DOUBLETAP_EXIT_ON_OPPOSITE_PATTERN	Set target and stop distances from pattern height and allow an opposite pattern to exit.
Risk and side policy	MAX_LOSS_VALUE, LONG.enable, LONG.direction, LONG.minRiskRatio, SHORT.enable, SHORT.direction, SHORT.minRiskRatio	Set the loss budget and enable each direction with its minimum reward-to-risk ratio.

Signal Payload

The strategy stores:

• additionalIndicators.doubleTapContext
• figures from buildDoubleTapFigures(...)
• stop at pattern.stopLossPrice
• one take-profit at pattern.targetPrice

Common Skip Reasons

• NO_PATTERN
• POSITION_EXISTS
• DEV_TRADE_COOLDOWN
• STRATEGY_DISABLED
• INVALID_QTY
• RISK_RATIO:<value>

Validation Notes

Use chart figures to confirm that the detected double top/bottom matches the structure you expected. Pattern engines are sensitive to pivot length and tolerance settings.