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reversal_patterns

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Reversal Pattern Research for Biotech Entry Triggers

Objective

This document organizes the main bullish reversal pattern families relevant for discretionary biotech trading and future systematic entry triggers. Focus is on patterns that can be translated into entry confirmation rules rather than vague visual labels.

1. Bullish Engulfing

Structure

  • Appears after a short-term down move
  • Candle 1: bearish real body
  • Candle 2: bullish real body that fully engulfs the prior real body

Visual

Conceptually: sellers press down, then buyers overwhelm the full prior day’s body.

What it means

This is one of the most common two-candle reversal patterns. It signals that supply was dominant on the prior bar, but the next session absorbed that selling and reversed control.

What matters most

  • Better after a clear downswing, not in random chop
  • Better when Candle 2 closes near the high
  • Better when volume expands
  • Better when it reclaims a reference level (prior day high, short MA, local support)

Strengths

  • Easy to define
  • Frequent enough for testing
  • Good as first-pass reversal trigger

Weaknesses

  • Too common by itself
  • Many false positives in volatile biotech names
  • Needs context filter

Best systematic use

Use as a confirmation bar, not a standalone signal. For example:

  • downtrend + oversold condition + bullish engulfing + close above prior candle high

2. Piercing Pattern

Structure

  • Appears after decline
  • Day 1: strong bearish candle
  • Day 2: opens weak / below prior close, then closes above the midpoint of Day 1 body
  • But does not fully engulf the whole body

Visual

Second candle penetrates deeply into prior bearish body.

What it means

Selling pressure was strong, but the next session rejects the weakness and recovers more than half the prior damage. It is weaker than a bullish engulfing but still important.

What matters most

  • Close above 50% of the prior body is key
  • Better if it also closes above prior open or near intraday high
  • Better near major support / prior breakdown area

Strengths

  • Captures early reversal attempts
  • Slightly more selective than many 1-candle reversals

Weaknesses

  • Often just a dead-cat bounce in high-vol biotech
  • Needs follow-through confirmation

Best systematic use

Require one more confirmation rule:

  • enter only if next day breaks Day 2 high

3. Morning Star

Structure

  • Three-candle bullish reversal
  • Candle 1: long bearish candle
  • Candle 2: small indecision candle / compressed body
  • Candle 3: strong bullish candle closing well into Candle 1 body

Visual

What it means

This pattern represents a transition:

  1. aggressive selling
  2. loss of downside momentum
  3. bullish takeover

Why traders like it

It expresses exhaustion + transition + confirmation better than simple 1-2 bar setups.

What matters most

  • Candle 1 should be meaningfully bearish
  • Candle 2 should show contraction / hesitation
  • Candle 3 should be strong and close deep into Candle 1 body
  • Extra strong if Candle 3 breaks structure, not just forms a green candle

Strengths

  • Strong narrative structure
  • Good visual clarity
  • Better reversal quality than many single-bar patterns

Weaknesses

  • Lower frequency
  • Gap logic from classic Japanese definitions matters less in modern equities
  • Can be too strict if coded literally

Best systematic use

Use a relaxed form:

  • large down bar
  • small hesitation bar
  • bullish reclaim bar that closes above prior 2-bar midpoint or breaks Day 1 high / Day 2 high

4. Bullish Key Reversal

Structure

  • During a down move, price makes a new low
  • Then reverses sharply and closes strongly higher
  • Often closes above prior close or above prior high in stricter versions

Visual

What it means

The market probes lower, finds liquidity, but cannot sustain lower prices. The same session flips control back to buyers.

This is very close to your style

Especially when you define it as:

  • break to new low
  • then bullish bar that reclaims prior bearish candle high

What matters most

  • New low should be meaningful (recent swing low, 20d low, support test)
  • Close should recover strongly from the low
  • Better if range is wide and volume is high

Strengths

  • Clear failed-breakdown logic
  • Good stop placement under the reversal low
  • Often catches sharp V-type turns

Weaknesses

  • Can be very noisy in biotech after news shocks
  • Needs context to avoid catching falling knives too early

Best systematic use

Define objective references:

  • new 20d low or break of prior swing low
  • close above prior candle high or above same-day midpoint threshold

5. Bullish Outside Reversal / Outside Bar Reversal

Structure

  • Current candle’s range exceeds prior candle’s entire range
  • Often low is lower than prior low and high is higher than prior high
  • Bullish version closes strong, ideally near high

Visual

What it means

Volatility expands and the current bar fully overwhelms the prior bar. In reversal context this shows a strong transfer of control from sellers to buyers.

Difference vs engulfing

  • Engulfing focuses on body
  • Outside reversal focuses on full range

What matters most

  • Strong bullish close matters more than just being outside
  • More meaningful after panic selloff / flush
  • Better with volume spike

Strengths

  • Strong momentum shift signal
  • Useful in volatile biotech names where body-only patterns miss intraday drama

Weaknesses

  • Can also appear in chaotic news-driven whipsaw
  • Needs location filter (near lows/support, not mid-range)

Best systematic use

  • outside bar + close in top 25% of daily range
  • ideally after short sequence of down bars

6. Wyckoff Spring

Structure

  • Price breaks below a known support / trading range low / prior swing low
  • Breakdown fails quickly
  • Price re-enters the prior range

Visual

What it means

This is a false breakdown / bear trap. Weak hands panic out, breakout sellers pile in, then price snaps back above support. That failed breakdown becomes the reversal catalyst.

Why it matters

For discretionary bottom-fishing, this is one of the most powerful concepts because it is not just a candle pattern — it is a liquidity event.

What matters most

  • Support level must be real
  • Breakdown should be rejected quickly
  • Reclaim should be decisive
  • Volume expansion often helps

Strengths

  • Strong structural logic
  • Very natural fit for biotech oversold reversals
  • Excellent risk definition: stop under spring low

Weaknesses

  • Support definition can be subjective
  • Some failed breakdowns keep failing again
  • News-driven collapses can invalidate springs fast

Best systematic use

  • break below prior N-day low or swing low
  • within 1-3 bars reclaim that low / support level
  • entry on reclaim or break of spring-bar high

7. 2B Reversal (Trader Vic style)

Structure

  • Market makes a new low versus a prior reference low
  • It fails to continue down
  • Then price turns back up through a nearby trigger level

Visual

What it means

This is the classic failed breakdown reversal pattern. It is closely related to the spring, but framed more explicitly as a failed new low rather than a trading-range event.

Why it is highly relevant here

Your discretionary rule:

  • a candle makes the new low
  • then a bullish candle breaks that low-candle’s high is almost a textbook 2B-style trigger.

What matters most

  • The prior low being violated should be meaningful
  • The new low should fail quickly
  • Entry trigger should be objective
    • close above low-bar high
    • or next day break above low-bar high

Strengths

  • Extremely easy to formalize
  • Very clean stop placement
  • Good combination of structure + confirmation

Weaknesses

  • Can trigger late if reclaim threshold is too strict
  • Too loose a prior-low definition creates noise

Best systematic use

This is probably the first one to test. Suggested prototype:

  • new 20-day low
  • within 3 bars price closes above the high of the low-setting candle
  • optional volume filter
  • optional oversold filter

8. 3-Bar Flush → Reclaim Pattern

Structure

This is not a classical named Japanese pattern, but a very tradable modern reversal structure.

  • 3 consecutive bearish candles
  • at least 2 of them push to lower lows
  • final bearish candle stretches downside momentum
  • next bullish candle breaks above the high (or body top) of the final bearish candle

Visual

  • Reference image: no single canonical textbook image exists for this exact setup
  • Recommended replacement: use a real market chart example extracted from our own v5.1/v6 trade charts where 3 consecutive bearish bars are followed by a reclaim of the last bearish candle high.
  • This one should be a custom example, not a generic web image.

What it means

This captures:

  • directional downside pressure
  • emotional flush
  • immediate reclaim / absorption

Why it fits biotech

Biotech names often overshoot to the downside over 2-4 sessions, then reverse violently when selling exhausts. This pattern is designed for that exact behavior.

What matters most

  • Consecutive down bars should be real, not tiny chop candles
  • Better if Bar 3 makes a short-term low extension
  • Better if Bar 4 is wide-range and closes strong

Strengths

  • Matches real discretionary trading behavior
  • Strong psychological logic
  • Can be parameterized flexibly

Weaknesses

  • Not standardized, so rules must be carefully defined
  • Too loose a version will overfire in noise

Best systematic use

Suggested prototype:

  • 3 consecutive down closes
  • bar 3 sets a 10-20d low or closes below BB lower band
  • entry when next bar breaks bar 3 high
  • optional requirement: volume on reclaim > 20d average

Practical Ranking for Systematic Testing

If the goal is biotech entry trigger research, the highest-priority patterns to test are:

  1. 2B Reversal / Spring reclaim
  2. 3-bar flush → reclaim
  3. Bullish key reversal
  4. Bullish outside reversal
  5. Morning Star (relaxed rules)
  6. Bullish engulfing
  7. Piercing pattern

Reason: the first 3 rely on structural failed breakdown logic, which is likely more robust in biotech than generic textbook candlestick labels.

How to Translate into an Entry Trigger Framework

Use this 3-layer structure:

Layer 1: Universe Filter

Examples:

  • top decile net_cash_to_mcap
  • min market cap
  • phase / dilution filters

Layer 2: Setup Context

Examples:

  • oversold state
  • recent downside sequence
  • local low test / breakdown attempt
  • BB lower band breach

Layer 3: Trigger

Examples:

  • break above low-bar high
  • break above final bearish candle high
  • close above reclaim threshold

This is the cleanest way to convert discretionary reversal trading into testable rules.

Preliminary Recommendation

For the next research phase, start with two formal candidates:

Candidate A: 2B / Spring Trigger

  • New 20-day low
  • Within 1-3 bars, price closes above the high of the low-setting bar
  • Optional: volume > 1.2x 20-day average

Candidate B: 3-Bar Flush Reclaim Trigger

  • 3 consecutive bearish closes
  • Final bar makes lower low and closes weak
  • Next bar breaks prior bar high
  • Optional: prior bar below BB lower band or SMA20 * 0.95

These two are the closest to your stated discretionary style and the easiest to formalize for backtesting.

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