Overview
Key findings
Statistical analysis of IS and CUSTOM execution across six core brokers. All figures winsorised P1/P99. Benchmark: is_at_touch_bps.
IS STRATEGY
ADV cliff at 3–5%
−5.9 bps
IS cost stays negative to 3% ADV. Sweet spot at 2–3% ADV. Cost turns positive and material above 5% ADV (+12.6 bps).
CUSTOM STRATEGY
Earlier cliff at 1–2%
+51.6 bps
CUSTOM breaks immediately at 1–2% ADV. Above 3% ADV mean exceeds +50 bps. Fundamentally different cost dynamics to IS.
VOLATILITY
Universal non-adaptation
+31 bps
Every broker accelerates in high vol — the opposite of optimal IS behaviour. 60+ bps cohort costs +31 bps mean. Route to JPM/CITI above 42 bps annualised.
TIME OF DAY
15:00 UTC peak cost
+21.3 bps
EMEA IS at 15:00–16:00 UTC (US open overlap) costs 16 bps more than the 16:00 window. Avoid high-participation arrivals in this window.
RANK PERSISTENCE
No monthly persistence
12/13
12 of 13 consecutive monthly broker IS rank-pairs show no significant correlation. Static TCA tiering has no statistical validity in this dataset.
APAC FILLS
Long-patience cluster
−20.8 bps
Long-duration APAC IS (>120 min) achieves the best outcomes in the dataset. 100% of high-quality fill proxy events are APAC. JPM leads this cohort.
Dataset
Coverage and strategy mix
Total orders
19,439
post-dedup, ex-LATAM
IS orders
6,776
34.9% of total
CUSTOM orders
4,241
21.8% of total
LATAM excluded
1,148
commission pool only
Notional
$22.6bn
USD, all strategies
Period
15 mo
Jan 2025 – Apr 2026
IS Strategy
ADV participation threshold
At what order size relative to ADV does IS cost turn positive? The 2–3% band is the sweet spot. The cliff is at 3–5%.
IS mean IS median CUSTOM mean CUSTOM median
IS stays negative to 3% ADV, CUSTOM turns positive at 1-2%.
IS sweet spot: 2–3% ADV (−5.9 bps mean). Cost is negative across the full 0–3% range. The cliff at 3–5% is real — mean flips to +2.5 bps, median to +8.75 bps.
CUSTOM has no sweet spot. Cost turns positive immediately at 1–2% ADV (+7.2 bps). Above 3% ADV the mean exceeds +50 bps. These are structurally different instruments.
IS Strategy
Order ADV × interval participation heatmap
For a given order size (columns), at what interval participation rate (rows) does cost become problematic? Key finding: interval participation rate is not the driver — order ADV size is.
strongly beneficial (<−15) beneficial neutral / sparse costly severely costly
Cost is driven by order ADV size, not pace. The <1% ADV row stays green or neutral across every interval participation rate — even at >25% pace. High interval participation in small orders reflects liquidity-seeking behaviour (dark pool, periodic auction) that aids performance, not market impact.
IS Strategy
Time of day — EMEA vs non-EMEA
Arrival hour UTC vs IS cost. The 15:00–16:00 UTC window (US open overlap into European close) is the most expensive IS window in the dataset.
IS EMEA IS non-EMEA
Peak EMEA IS cost at 15:00 UTC. Non-EMEA consistently negative.
15:00–16:00 UTC: +21.3 bps EMEA IS mean. This is 16 bps above the 16:00 window (+5.2 bps). Avoid initiating high-participation EMEA IS orders in this window where possible.
Non-EMEA is consistently negative — APAC and Americas IS orders show beneficial outcomes across most hours, confirming the regional cost asymmetry.
IS Strategy
Volatility regime × ADV participation
Vol regime compounds participation cost. The same order in high vol costs materially more than in low vol at every ADV band.
low <28 bps normal 28–42 elevated 42–60 high >60 bps
High vol compounds cost materially at every participation level.
Universal algo design flaw: every broker accelerates in high volatility — the opposite of optimal IS behaviour. Confirmed for all 6 brokers at p<0.01.
Route IS to JPM or CITI above 42 bps annualised vol. Avoid UBS, BARC, BofA in elevated vol conditions.
IS Strategy
Broker × ADV participation band
How each broker's IS cost varies by order size. Reveals which brokers maintain performance as participation increases.
Broker IS cost by ADV participation band.
Select a broker to see their IS cost profile by ADV participation band.
CUSTOM Strategy
ADV participation threshold
91.3% of CUSTOM orders complete in under 1 minute — these are single-event crosses. Cost dynamics are structurally different from IS.
Instant fills <1min
91.3%
single-event crosses
APAC mean cost
−5.5 bps
vs EMEA +32.7 bps
Cost cliff
1–2% ADV
turns positive immediately
Notional cliff
≥USD 1m
mean jumps to +41 bps
CUSTOM mean CUSTOM median
CUSTOM cost escalates sharply above 1% ADV.
CUSTOM Strategy
Spread quality × notional size
Unlike IS, CUSTOM cost is driven primarily by notional size — not spread quality. Tight spread instruments still incur high cost above USD 2m.
Notional size dominates spread quality above USD 1m. Tight spread instruments at USD 2–5m cost +13.5 bps mean — almost as costly as wide spread at the same size. The exception: wide spread / USD 500k–1m (−25.8 bps, n=96) likely reflects strong periodic auction or dark pool fills in mid-cap European instruments.
CUSTOM Strategy
Broker performance
BARC and BofA show inverted rankings vs IS — confirmed across two independent weight windows. A single weight vector is structurally wrong for both strategies.
BARC lowest CUSTOM cost, BofA highest. Mean/median gap reveals tail vs systematic performance.
BARC and UBS median = 0.00 bps — the majority of their CUSTOM orders execute at benchmark. Elevated means are tail events, not systematic failure.
BofA median = +20.4 bps — this is systematic underperformance, not skew. Confirmed p=0.008.
IS-CUSTOM inversion: BARC underperforms IS but leads CUSTOM. BofA leads IS but underperforms CUSTOM. Strategy-conditional bandit instances are required.
Recommender
Value proposition vs random algowheel
Monetary estimate of routing intelligence vs a v1 random algowheel with zero routing logic. IS flow only; CUSTOM upside excluded pending W2 spike investigation.
IS annual notional
~$5.5bn
annualised run rate
Exploitable flow
~30%
high-vol + high-par
Conservative recovery
10 bps
50% capture rate
IS annual saving
$1–2m
central estimate
CUSTOM upside
$1–2m
directional — blocked
Combined range
$2–4m
per year at run rate
ConditionRandom costRouted costRecoverableConfidence
Vol >60 bps IS+31 bps~+8 bps (JPM/CITI)~22 bpsHigh — p<0.01 all brokers
High-par IS (>3% ADV)+26.8 bps~+8 bps (patient routing)~18 bpsHigh — rho=0.181, p<0.0001
Fast-illiquid IS+32.2 bps+25 bps (patient broker)~7 bpsHigh — p=0.044
Long APAC patience~−5 bps (random hit rate)−20.8 bps (targeted)~15 bpsMedium — n=118
CUSTOM IS-inversionBARC/BofA random mixStrategy-conditional~14 bpsHigh — two windows confirmed
Conclusion
Expert assessment

// RECOMMENDER vs RANDOM — VERDICT: B

The recommender is the correct choice, unambiguously. Random allocation is the naive comparator — and the data quantifies the margin it leaves on the table at USD 1–2m per year on IS flow alone at current run-rate notional.

The volatility non-adaptation finding alone justifies the system. Every broker accelerates in high volatility — the opposite of optimal IS behaviour, confirmed for all six brokers at p<0.01. Random allocation routes to UBS or BARC in a high-vol EMEA IS order as often as it routes to JPM or CITI. The recommender routes to JPM or CITI every time that condition is met.

The IS-CUSTOM inversion for BARC and BofA is confirmed across two independent weight windows. A single weight vector is structurally wrong for both strategies simultaneously. Strategy-conditional bandit instances are required architecture, not an optimisation.

Build now: IS bandit with strategy conditioning, LATAM excluded from reward signal, participation rate as primary routing gate, confidence-weighted by broker sample density.

Do not build yet: CUSTOM reward function — W2 spike of +44.8 bps requires investigation with LiquidMetrix before the signal is trustworthy.

Immediate action: UBS is the only significantly elevated IS broker in W2 (p=0.013). TS implied weight 0.6%. Current 18% allocation is not supported by evidence.

Source: latest.parquet, 19,439 orders, Jan 2025–Apr 2026. LATAM (1,148 orders) retained in commission pool, excluded from all performance analysis. Methods: Mann-Whitney U two-sided; Spearman rank correlation; K-means k=5; Thompson Sampling Gaussian conjugate posterior. Winsorisation: global P1/P99. Commission: 3 bps × USD 22.56bn annualised = USD 6.77m pool.