CtrlK
BlogDocsLog inGet started
Tessl Logo

etf-premium

Calculate ETF premium/discount vs NAV via Yahoo Finance, and decompose single-day surges into NAV-driven vs structural components (gamma squeeze, dealer hedging, blocked AP arbitrage). Use whenever the user asks about an ETF's premium or discount, NAV comparison, why an ETF diverged from its holdings, or how much of a move is dealer-hedging-driven. Triggers: "ETF premium", "ETF discount", "NAV premium", "is SPY at a premium", "BITO premium", "IBIT premium", "bond ETF discount", "trading above/below NAV", "ETF premium screener", "biggest discount", "compare ETF NAV", "ETF arbitrage", "ETF gamma squeeze", "ETF premium surge", "decompose ETF move", "dealer gamma exposure", "GEX for ETF", "why did this ETF jump", "premium convergence", "AP arbitrage blocked", or any request about the gap between an ETF's price and underlying value. Especially relevant for leveraged, inverse, international, bond, commodity, and crypto ETFs.

69

Quality

84%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

68%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, code-rich skill body with strong routing and clearly signaled reference files, but it leans slightly long with occasional over-explanation and inlines detailed sub-skill content that could be offloaded. Batch/screening workflows lack explicit validation feedback loops, capping workflow clarity.

Suggestions

Trim or remove the 'Why this matters' paragraph and other conceptual explanations Claude can infer (e.g. 'When you buy at a premium, you're overpaying...') to improve conciseness.

Add explicit validation/error-recovery checkpoints to the Sub-Skill C screener (e.g., retry on failed tickers, report and handle missing-NAV counts as a feedback loop) to lift workflow clarity above the batch-operation cap of 3.

Move the full Sub-Skill E (E1-E5) detail and the inline CATEGORY_PEERS dictionary into a reference file, keeping only routing and the headline decomposition table in SKILL.md, to strengthen progressive disclosure.

DimensionReasoningScore

Conciseness

Mostly efficient and code/table-heavy, but a few sections over-explain concepts Claude already knows, e.g. 'When you buy at a premium, you're overpaying relative to the assets; at a discount, you're getting a bargain' — minor padding that could be trimmed. Not a 5 because of the 'Why this matters' block and incidental explanatory prose; not a 3 because the bulk assumes competence.

4 / 5

Actionability

Provides copy-paste-ready Python for Sub-Skills A and B and concrete formulas for E1/E3, with dependency-install commands and clear routing. Not a 5 because Sub-Skills C, D, and E2 delegate the executable GEX computation to reference files rather than providing complete inline code, leaving minor gaps.

4 / 5

Workflow Clarity

Steps are clearly sequenced (deps -> route -> sub-skills -> respond) with some validation (DEPS_MISSING check, quoteType/NAV guards), but the batch screener (Sub-Skill C) lacks explicit validation or error-recovery checkpoints, capping this at 3 per the batch-operations guideline. Not a 2 because the sequence is well-defined; not a 4 because feedback loops for the batch and data-fetch workflows are absent.

3 / 5

Progressive Disclosure

SKILL.md is an overview pointing to two clearly signaled one-level-deep reference files (both verified to exist in references/), with a well-organized routing table. Not a 5 because substantial detailed content — the full five-step Sub-Skill E and large inline category peer dicts — is inlined rather than split out, a minor organization gap.

4 / 5

Total

15

/

20

Passed

Description

100%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description is exemplary: it states concrete capabilities, gives an explicit 'Use whenever' trigger clause, lists a comprehensive set of natural user phrasings including specific tickers, and carves out a distinctive niche. Strong third-person voice throughout with no fluff.

DimensionReasoningScore

Specificity

Lists multiple concrete actions — 'Calculate ETF premium/discount vs NAV' and 'decompose single-day surges into NAV-driven vs structural components (gamma squeeze, dealer hedging, blocked AP arbitrage)' — with comprehensive coverage of the skill's capabilities.

5 / 5

Completeness

Explicitly answers both 'what' (calculate premium/discount, decompose surges) and 'when' via a 'Use whenever...' clause plus a long list of concrete trigger phrases.

5 / 5

Trigger Term Quality

Extensive natural trigger phrases users would actually say, including synonyms (premium/discount, NAV), specific tickers ('is SPY at a premium', 'BITO premium', 'IBIT premium'), and varied phrasings ('why did this ETF jump', 'trading above/below NAV').

5 / 5

Distinctiveness Conflict Risk

A clear niche (ETF premium/discount vs NAV with gamma-squeeze decomposition) anchored by distinct triggers, with minimal realistic overlap against other skills.

5 / 5

Total

20

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository
himself65/finance-skills
Reviewed

Table of Contents

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.