ModelsICT Trading EducationM12
ICT Sick Sister Strategy: How to Trade the Weakest Market
When two correlated markets should move together but one refuses to follow, that laggard — the “sick sister” — is telling you where the real weakness sits. This is how Inner Circle Traders turn correlation divergence into a directional edge.
The Inner Circle Traders
Updated August 2026
11 min read
Cluster: Models
Key Takeaways
- The Sick Sister strategy compares two positively correlated markets and trades the weaker one — the "sick sister" that fails to make an equivalent high or low
- It is a practical application of SMT divergence: when correlated pairs diverge, the underperformer reveals institutional intent
- The strongest sick-sister setups appear at a known draw on liquidity and inside a kill zone, not at random times
- Confirmation comes from a lower-timeframe market structure shift in the weak pair after the divergence prints
- Common correlated sets: EURUSD/GBPUSD, ES/NQ, and USD pairs against DXY (which is read inversely)
What Is the Sick Sister Strategy?
The ICT Sick Sister strategy is a correlation-based technique that identifies the weaker of two markets that normally move together, and trades in the direction that weakness implies. When two positively correlated instruments should be making matching highs or lows and one of them fails to keep up, that lagging market is the “sick sister.” Its failure is not random — it is a footprint of where institutional order flow is genuinely weighted.
Michael Huddleston teaches this as an extension of correlated-pair analysis rather than a stand-alone system. It answers a specific question: when the market gives you two candidates and you can only trade one cleanly, which one offers the higher-probability move? The sick sister does, because it is already showing you it cannot follow strength.
Definition
The sick sister is the correlated market that fails to confirm the move of its stronger counterpart — for example, failing to make a new high when its partner does. That failure signals the direction of least resistance.
The Correlation Logic
Two markets are positively correlated when they tend to move in the same direction. EURUSD and GBPUSD are the classic Forex example: both are quoted against the US dollar, so dollar strength or weakness pushes them together most of the time. In index futures, the S&P 500 E-mini (ES) and the Nasdaq (NQ) behave the same way.
Correlation is only useful to an ICT trader at the moments it breaks. When both markets rally together, there is no information. When one rallies to a new high and the other cannot, the divergence tells you that the buying pressure is not uniform — and the market that failed is the one carrying the hidden weakness.
How to Identify the Sick Sister
The process is mechanical:
1. Pick a correlated pair
Choose two instruments with a reliable positive correlation and put them on side-by-side charts at the same timeframe.
2. Mark the reference swing
Find a recent significant high or low that both markets pushed toward. This is your comparison point.
3. Watch the retest
When price returns to that level, compare: did both markets make an equal high (or low), or did one fall short? The one that fails to reach an equivalent extreme is the sick sister.
Reading Tip
A sick sister that fails to make a higher high while its partner does is signalling bearish intent. A sick sister that fails to make a lower low is signalling bullish intent. You trade the failure, not the strength.
The SMT Divergence Connection
If this sounds like SMT divergence, it should — the sick sister is SMT divergence applied as a selection filter. SMT (Smart Money Technique) divergence is the underlying signal; the sick sister framing tells you what to do with it: trade the weak leg.
This matters because traders often see divergence and hesitate over which market to execute in. The sick sister rule removes that hesitation. The divergence identifies the pair; the weak pair is your instrument.
Entry, Stop and Target Framework
Entry
Do not enter on the divergence alone. Drop to a lower timeframe on the sick sister and wait for a market structure shift in the direction the divergence implies. That shift — a break of the most recent short-term swing against the failed move — is your trigger. Refine the entry into the resulting fair value gap or order block.
Stop
Place the stop beyond the extreme the sick sister just failed to break. If it failed to make a higher high, your stop sits above that failed high — if price reclaims it, the divergence is invalid.
Target
Target the opposing liquidity: the nearest buy-side or sell-side pool that represents the logical draw on liquidity.
A Worked Example
Assume EURUSD and GBPUSD are both rallying into the London session. Both run into an old high (buy-side liquidity). EURUSD pushes to a clean new high; GBPUSD stalls just short and fails to take its equivalent high. GBPUSD is the sick sister.
You drop GBPUSD to the 5-minute chart, wait for a bearish market structure shift below the last up-swing, and enter short on the retracement into the fair value gap left by the displacement. Stop goes above GBPUSD’s failed high; target is the sell-side liquidity resting below the session low. The weakness GBPUSD showed at the highs is what carries the trade down.
Best Correlated Pairs to Use
Forex
EURUSD / GBPUSD
The most reliable positive correlation for the sick sister setup during London and New York sessions.
Index Futures
ES / NQ
S&P 500 and Nasdaq diverge frequently at session highs and lows — excellent for intraday sick-sister reads.
Dollar Index
EURUSD / DXY
Read inversely: EURUSD and DXY are negatively correlated, so divergence is judged against opposite extremes.
Common Mistakes
Trading the divergence without a structure shift. Divergence identifies weakness; it is not an entry. Without a confirming market structure shift you are guessing.
Using unrelated pairs. The correlation must be genuine and current. Correlations drift; check that the two markets are actually moving together before relying on their divergence.
Ignoring the draw on liquidity. A sick sister that diverges in the middle of a range is far weaker than one that diverges at a clear liquidity objective. Context is everything.
Frequently Asked Questions
What is the ICT Sick Sister strategy?+
It is a correlation-based ICT technique that identifies the weaker of two positively correlated markets — the one that fails to confirm its partner's high or low — and trades in the direction that weakness implies, confirmed by a lower-timeframe market structure shift.
How is the sick sister different from SMT divergence?+
SMT divergence is the underlying signal. The sick sister framing is how you act on it: it tells you to execute in the weaker (divergent) market rather than the stronger one.
Which pairs work best for the sick sister setup?+
Positively correlated instruments with reliable, current correlation: EURUSD/GBPUSD, ES/NQ, and gold/silver. DXY can be used but is read inversely against dollar pairs.
Do I enter as soon as I see the divergence?+
No. The divergence only identifies the pair and direction. You wait for a market structure shift on a lower timeframe in the sick sister and refine the entry into the resulting fair value gap or order block.
Where do I place the stop loss?+
Beyond the extreme the sick sister failed to break. If it failed to make a higher high, the stop sits above that failed high; a reclaim invalidates the divergence.
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