WILLIAM BLAIR (CRD #1252) — Quarterly Rule 606 vs. Amended Rule 605 Competing Market Review
Rule 5310.09 Exceptions Preview (0 Total)
All scored order size and routing buckets where venue net price improvement trailed mix-adjusted peers by > 1.0 bps.
No statistically significant competing-market shortfalls exceeding 1.0 bps were detected in this quarter’s scored cells.
WILLIAM BLAIR
Resolved Rule 606 Source Filings
| Author / Clearing Firm | CRD | Variant / Context | Version | SHA-256 Digest | Source Document |
|---|---|---|---|---|---|
| William Blair Sell Side | 1252 | Direct | V1 | a10f7982aa10674b868f9ae0cd29aa900ff3d571a8e6eff0473ff3efeabc8a17 | Download XML ↗ |
1. SEC Rule 606(a)(1) Order Routing
Quarterly non-directed customer order routing shares and net PFOF/rebates by section and venue.
| Month | Section | Execution Venue | 605 Reporter | Route % | Market % | Mkt Limit % | Non-Mkt % | PFOF Mkt (¢/100) | PFOF Limit (¢/100) |
|---|---|---|---|---|---|---|---|---|---|
| 202601 | options | Citadel Securities LLC (CDRG) | Unmapped | 34.9% | 36.5% | 30.6% | 36.6% | 0.00 ¢ | 0.00 ¢ |
| 202601 | options | Jane Street Capital LLC (JNST) | Unmapped | 24.9% | 27.2% | 13.9% | 22.8% | 0.00 ¢ | 0.00 ¢ |
| 202601 | options | GLOBAL EXECUTION BROKERS LP (GEBB) | Unmapped | 16.1% | 19.3% | 13.9% | 3.6% | 0.00 ¢ | 0.00 ¢ |
| 202601 | options | Dash Financial Technologies LLC(DASH) | Unmapped | 13.9% | 12.3% | 30.6% | 11.4% | 0.00 ¢ | 0.00 ¢ |
| 202601 | options | Wolverine Execution Services LLC(WEXX) | Unmapped | 9.6% | 4.6% | 2.8% | 24.2% | 0.00 ¢ | 0.00 ¢ |
| 202601 | other_stocks | Virtu Americas LLC (NITE) | Unmapped | 33.4% | 33.7% | 29.2% | 32.6% | 0.00 ¢ | 0.00 ¢ |
| 202601 | other_stocks | Citadel Securities LLC (CDRG) | Unmapped | 33.2% | 33.2% | 41.6% | 34.1% | 0.00 ¢ | 0.00 ¢ |
| 202601 | other_stocks | Wall Street Access (VNDM) | Unmapped | 32.9% | 33.1% | 29.2% | 33.3% | 0.00 ¢ | 0.00 ¢ |
| 202601 | sp500 | Citadel Securities LLC (CDRG) | Unmapped | 33.5% | 33.7% | 36.6% | 32.8% | 0.00 ¢ | 0.00 ¢ |
| 202601 | sp500 | Wall Street Access (VNDM) | Unmapped | 33.0% | 33.4% | 27.7% | 32.5% | 0.00 ¢ | 0.00 ¢ |
| 202601 | sp500 | Virtu Americas LLC (NITE) | Unmapped | 32.8% | 32.9% | 35.7% | 34.7% | 0.00 ¢ | 0.00 ¢ |
| 202602 | options | Citadel Securities LLC (CDRG) | Unmapped | 34.2% | 35.7% | 35.3% | 27.7% | 0.00 ¢ | 0.00 ¢ |
| 202602 | options | Jane Street Capital LLC (JNST) | Unmapped | 24.1% | 26.8% | 14.7% | 20.6% | 0.00 ¢ | 0.00 ¢ |
| 202602 | options | GLOBAL EXECUTION BROKERS LP (GEBB) | Unmapped | 17.8% | 21.4% | 14.7% | 8.8% | 0.00 ¢ | 0.00 ¢ |
| 202602 | options | Dash Financial Technologies LLC(DASH) | Unmapped | 14.4% | 11.6% | 11.8% | 19.8% | 0.00 ¢ | 0.00 ¢ |
| 202602 | options | Wolverine Execution Services LLC(WEXX) | Unmapped | 9.3% | 4.6% | 20.6% | 22.4% | 0.00 ¢ | 0.00 ¢ |
| 202602 | other_stocks | Citadel Securities LLC (CDRG) | Unmapped | 33.7% | 33.6% | 40.9% | 36.5% | 0.00 ¢ | 0.00 ¢ |
| 202602 | other_stocks | Wall Street Access (VNDM) | Unmapped | 32.9% | 33.3% | 26.4% | 31.5% | 0.00 ¢ | 0.00 ¢ |
| 202602 | other_stocks | Virtu Americas LLC (NITE) | Unmapped | 32.9% | 33.1% | 32.7% | 32.0% | 0.00 ¢ | 0.00 ¢ |
| 202602 | sp500 | Virtu Americas LLC (NITE) | Unmapped | 32.9% | 33.6% | 30.6% | 32.1% | 0.00 ¢ | 0.00 ¢ |
| 202602 | sp500 | Wall Street Access (VNDM) | Unmapped | 32.7% | 33.1% | 34.3% | 36.1% | 0.00 ¢ | 0.00 ¢ |
| 202602 | sp500 | Citadel Securities LLC (CDRG) | Unmapped | 32.6% | 33.3% | 35.1% | 31.8% | 0.00 ¢ | 0.00 ¢ |
| 202603 | options | Citadel Securities LLC (CDRG) | Unmapped | 36.9% | 38.4% | 40.7% | 29.6% | 0.00 ¢ | 0.00 ¢ |
| 202603 | options | Jane Street Capital LLC (JNST) | Unmapped | 23.8% | 25.1% | 37.0% | 20.9% | 0.00 ¢ | 0.00 ¢ |
| 202603 | options | GLOBAL EXECUTION BROKERS LP (GEBB) | Unmapped | 16.2% | 18.1% | 7.4% | 10.3% | 0.00 ¢ | 0.00 ¢ |
| 202603 | options | Dash Financial Technologies LLC(DASH) | Unmapped | 14.9% | 14.4% | 3.7% | 16.6% | 0.00 ¢ | 0.00 ¢ |
| 202603 | options | Wolverine Execution Services LLC(WEXX) | Unmapped | 7.9% | 3.9% | 11.1% | 22.6% | 0.00 ¢ | 0.00 ¢ |
| 202603 | other_stocks | Citadel Securities LLC (CDRG) | Unmapped | 33.9% | 33.9% | 40.5% | 33.4% | 0.00 ¢ | 0.00 ¢ |
| 202603 | other_stocks | Virtu Americas LLC (NITE) | Unmapped | 33.1% | 33.3% | 30.8% | 33.7% | 0.00 ¢ | 0.00 ¢ |
| 202603 | other_stocks | Wall Street Access (VNDM) | Unmapped | 32.7% | 32.8% | 28.6% | 32.9% | 0.00 ¢ | 0.00 ¢ |
| 202603 | sp500 | Wall Street Access (VNDM) | Unmapped | 33.3% | 33.6% | 37.6% | 32.7% | 0.00 ¢ | 0.00 ¢ |
| 202603 | sp500 | Virtu Americas LLC (NITE) | Unmapped | 33.0% | 33.5% | 30.9% | 32.7% | 0.00 ¢ | 0.00 ¢ |
| 202603 | sp500 | Citadel Securities LLC (CDRG) | Unmapped | 32.5% | 32.8% | 31.5% | 34.6% | 0.00 ¢ | 0.00 ¢ |
2. Venue Scorecards (Amended Rule 605)
Execution quality metrics for routed venues benchmarked against mix-adjusted competitors on identical symbols and size tiers.
| Month | Venue | Class | Notional × Lot | Fill Rate | PI Rate | NPI (bps) | Peer Bench (bps) | Coverage | Rank Pctl | Eff Spread | Speed <1s |
|---|
3. Routing-Weighted Composite Quality
Implied execution quality achieved by the firm’s routing mix across the 24 amended size tiers, compared against the best and median competing venues.
| Month | Class | Notional × Lot | Metric | Firm Composite | Best Competing | Best Venue | Median Competing | Mapped Flow |
|---|
4. Payment for Order Flow vs. Execution Quality
Addresses FINRA 5310.09 conflicts: comparing PFOF received (¢/100 sh) against net price improvement shortfall vs mix-adjusted peers.
| Month | Venue | Order Class | Route % | 606 Net PFOF (¢/100) | NPI (bps) | Peer Bench (bps) | Delta (bps) | Ref Price | Delta (¢/100 sh) | Conflict Flag |
|---|
Conflict Methodology Note: Quality delta (¢/100 sh) is estimated as Δ_bps × ref_price. A positive PFOF beside a negative delta indicates the firm received payment while the venue delivered less price improvement than competing market centers on identical symbols and size tiers.
5. Material Changes Since Prior Quarter
Changes in routing share (≥ 5 pp), newly added/dropped venues, and PFOF rate shifts since 2025Q4.
No material shifts (≥ 5 percentage point route share or PFOF rate change) detected relative to 2025Q4.
6. Coverage, Exclusions & Standing Limitations
Mandatory regulatory disclosure of data availability, unmapped destinations, and methodological caveats.
Unmapped Routing Destinations:
Citadel Securities LLC (CDRG) (name:CITADEL SECURITIES LLC CDRG), Virtu Americas LLC (NITE) (name:VIRTU AMERICAS LLC NITE), Wall Street Access (VNDM) (name:WALL STREET ACCESS VNDM)
Standing Review Limitations:
- A venue's Rule 605 statistics describe all flow it handled, not this firm's orders.
- 606 route shares are per order, not per share, and list only the top 10 venues plus any venue with at least 5% of non-directed orders.
- FINRA Rule 5310.09 also requires the firm's own order-level review of its executions.
- This report is not legal or compliance advice.
- Net price improvement is in basis points of executed notional (quote midpoint × shares). The PFOF comparison converts the difference to ¢/100 sh at the venue's average executed price; it is an estimate.