execution-algorithmslisted
Install: claude install-skill howard-lynn-ye/fin-skills
# Execution algorithms
**Every schedule is optimal for something. The failure is not choosing badly — it is not
knowing what your schedule was chosen to minimize, and then reporting it against a benchmark
that measures something else.**
Everything marked ✅ Measured comes from `scripts/execution_algos.py` — numpy + pandas, seed
20260909, one 390-bin session plus closed forms, **2 s**. Everything marked ✅ source-verified
was read by this library in the December 2000 Almgren-Chriss preprint; the equation numbers are
as printed there and the full transcription is in the script's docstring.
This skill is the **schedule**. `../../../fin-core/skills/execution-cost-analysis/SKILL.md` is
the **measurement** of fills you already have — read it for benchmark choice, the reversion
test, and what to log per parent order. §3 below is the one place they touch, and it is a
different mechanism, stated as such.
## 1. The four schedules, and what each one ignores
| Schedule | Minimizes | Blind to |
|---|---|---|
| **TWAP** | nothing; it spreads evenly | volume, entirely |
| **VWAP** | tracking error to the session VWAP | whether trading at the market's pace was wise |
| **POV `r`** | footprint per bin | **completion — it can simply not finish** |
| **Almgren-Chriss** | `E[cost] + λ·Var[cost]` | the volume profile; it is a clock, not a participation rule |
✅ Measured — 250,000 shares against a 5M-share session drifting +59 bps against the buyer,
with Almgren-Chriss linear impact applied: