ml4t-transaction-costs SKILL.md skillA
ml4t-transaction-costs from ml4t/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ml4t/skills/ml4t-transaction-costs@git:20260901.c415df0Pins git:20260901.c415df0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ml4t/skills
- Path
concepts/transaction-costs/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260901.c415df0, committed Sep 1, 2026
- First version recorded
- May 28, 2026
- Size
- 4,108 bytes
- Repository stars
- 41
- License
- Apache-2.0
Estimate whether a strategy can survive spread, slippage, and market impact before full simulation. Use when screening strategy feasibility early.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Transaction Cost Feasibility Before you wire costs into a backtest engine, ask a simpler question: does the signal have enough gross edge to pay for trading at all? If not, the strategy should die early. ## The Problem The full cost of a trade has three layers: explicit costs (commissions, fees), implicit costs (half the bid-ask spread paid on every execution), and market impact (your own order moving the price against you). Most bad strategies fail this economic screen before any engine-specific implementation details matter. A strategy with 50 bps gross alpha and 30 bps round-trip costs has a safety margin of only 1.7x - too thin to survive estimation error. ## The Pattern ### WRONG ```python import numpy as np # Flat cost assumption - ignores volume dependence weights = compute_target_weights(signals) turnover = np.abs(weights - prev_weights).sum() costs = turnover * 0.001 # 10 bps flat - wrong for large trades net_return = gross_return - costs ``` ### CORRECT ```python import numpy as np weights = compute_target_weights(signals) turnover = np.abs(weights - prev_weights) # Volume-dependent square-root impact model …
Read the whole file at its exact version.
How to install
mdr add ml4t/skills/ml4t-transaction-costs@sha256:d05ca6174949ff57The line at the top of this page pins the label git:20260901.c415df0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_rnuf2hloxiiaoltj)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 28, 2026 and Sep 1, 2026, about one every 96 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260901.c415df0 latest | 2026-09-01 | c415df0 | 4,108 B | A | view · diff |
| git:20260528.303089e | 2026-05-28 | 303089e | 4,118 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4108 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
ml4t/skills · 41 stars · license Apache-2.0 · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rnuf2hloxiiaoltj GET https://markdownregistry.com/api/v1/resolve?ref=ml4t/skills/ml4t-transaction-costs GET https://markdownregistry.com/api/v1/blob/d05ca6174949ff57f4bae3b99550a5a00c4a065c9946a9f1a34ca1898afe2c1c
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.