Indexedhimself65/finance-skills

ETF Premium/Discount AnalysisFinance Skill

A four-file workflow for ETF snapshots, comparisons, screening and holdings/options scenarios using yfinance. The basic price-to-NAV formula is clear, but price/NAV timestamps and holdings coverage require verification. The GEX explanation contradicts its stated dealer positions and overstates what open interest can reveal about actual buying and convergence. Read the high-risk findings before using the examples; no dealer-flow measurement or tested squeeze forecast is provided.

Assessment score
75/100
Snapshot risk
High
Audit conclusion
Needs review
How the assessment score works

Pineify weights evidence recorded from the captured files: Skill structure 15%, Instruction clarity 20%, Dependency transparency 20%, Permission transparency 20%, Safety guardrails 15%, Finance task fit 10%. Each signal receives full credit for Yes, one-quarter credit for unknown, and none for No.

The score is not an output accuracy test or user rating. Read the findings and financial assumptions even when the score is high. Risk labels summarize recorded permissions and findings; they do not measure investment risk or certify that installation is safe.

Discovery

What this Skill helps an agent do.

Use the tasks and topics below to judge whether the captured workflow fits your question. Read its findings, dependencies and data requirements before relying on an output.

Finance tasks

Etf premium analysisOptions analysisScreener analysis

Domains and assets

Equity researchTechnical analysisPublic equities

Topics

etf-premiumetf-discountnavgamma-squeezedealer-hedginggexoptions-flowetf-screenerap-arbitragepremium-decomposition

Trust

Evidence from the captured directory.

This content snapshot assessment does not certify the repository, current files, or installation environment. "Not verified" means the captured files did not support a Yes or No conclusion.

License

MITYes

GitHub reports the repository license as MIT License.

Review state

Automated review
Automated review
Install tested
No
Human reviewed
Not verified

Snapshot

Files reviewed
4
Captured
2026-07-29 07:31 UTC
Snapshot ID
fsh-etf-premium-2026-07-29-001

Permissions

FilesystemRead

Yes

The workflow reads two bundled references and checks installed Python packages.

FilesystemWrite

Yes

The documented pip command installs dependencies into the Python environment when missing.

NetworkAccess

Yes

yfinance pulls ETF info, NAV, holdings, options chains, and historical prices from Yahoo Finance APIs. Screener mode fetches data for 60+ tickers.

ShellExecution

Yes

The skill executes Python scripts in the shell for data fetching, premium calculation, GEX computation, and surge decomposition. Auto-installs yfinance, pandas, numpy via pip if missing.

CodeExecution

Yes

The skill executes Python code including Black-Scholes gamma calculation, GEX aggregation, premium decomposition, volatility annualization, and dealer share estimation.

ExternalCredentials

No

No external credentials are required — yfinance uses public Yahoo Finance APIs.

Dependencies

yfinance

python3 -m pip install yfinance (auto-installed if missing)

Yes

Python library for pulling Yahoo Finance ETF info, NAV, holdings, options chains, and price history.

pandas

python3 -m pip install pandas (auto-installed if missing)

Yes

Data manipulation library for handling ETF premium DataFrames and options chain data.

numpy

python3 -m pip install numpy (auto-installed if missing)

Yes

Numerical computing library used in volatility annualization and gamma exposure calculations.

Python 3.8+

Python 3.8 or later

Yes

Python runtime required for yfinance data fetching and all analytical computations.

Data sources named by the Skill

Yahoo Finance (yfinance)

Python library providing access to Yahoo Finance ETF data including navPrice, options chains, funds_data, and price history.

Snapshot assessment

75/100

Pineify Finance Skill snapshot assessment, version 1.0.0. Generated 2026-10-20 00:00 UTC.

High risk · Needs review

Skill structure

100/100

Instruction clarity

100/100

Dependency transparency

45/100

Permission transparency

75/100

Safety guardrails

56/100

Finance task fit

80/100

Audit findings

High

Open interest does not identify dealer flows

Open interest supplies neither dealer ownership nor net long/short positioning. Multiplying one gamma snapshot by the full daily move is a scenario approximation, not observed buying or a guaranteed upper bound on intraday hedge turnover. The DRAM worked example explicitly labels its source-article figures unverified and notes that its dollar GEX does not reconcile; do not present the 35% dealer share, squeeze diagnosis or convergence timetable as measured facts.

High

Gamma signs and expiry behavior need correction

The source assumes dealers short calls and long puts, yet calculates call gamma minus put gamma and interprets it as dealer gamma. Those stated positions instead have negative call and positive put gamma. Long calls and puts have positive gamma; short positions have negative gamma. Gamma need not decay near expiry: it can rise sharply at the money. A fixed options-expiry date therefore does not establish a squeeze-convergence deadline.

High

A holdings residual is not a measured premium cause

Synchronize price and NAV valuation timestamps before calling their difference a current premium. Normalizing a partial holdings list assumes omitted assets behave like included ones; FX, distributions, cash, derivatives, leverage and nonoverlapping sessions need separate treatment. Price return minus a holdings-return proxy is a percentage-point residual, not the exact premium change or evidence of gamma/AP constraints. A US listing does not show that underlying markets are open, and a single AUM value is not net flow.

Medium

Category ranges and model shortcuts are unverified

The category premium bands and hours/days/weeks convergence claims have no dated supporting dataset here. Roll costs and leverage compounding affect fund returns and NAV; they do not by themselves prove price/NAV mispricing. A spread comparison alone cannot establish mispricing or dismiss it. The code also uses UTC midnight expiry, assumes a 100 multiplier, omits dividend yield in gamma, loses valid zeros through truthiness checks, and silently skips failed holdings or tickers. Check actual contract terms, price/IV timestamps, coverage and missing values before interpretation.

Medium

Dependency manifest is absent from the snapshot

No requirements.txt or pyproject.toml is included in the captured directory. Dependencies are documented in README and auto-installed if missing.

Low

Auto-installs Python dependencies via pip if missing

The skill auto-installs yfinance, pandas, and numpy via subprocess.check_call([sys.executable, "-m", "pip", "install", "-q", "yfinance", "pandas", "numpy"]) when not detected. This modifies the user Python environment.

Low

GEX computation is sensitive to dealer-positioning assumptions

The skill computes GEX using two conventions (SqueezeMetrics net GEX and customer-net-long gross hedge) and explicitly warns that results can differ by orders of magnitude depending on convention. The reference file includes a worked example where the article figures do not reconcile, illustrating the sensitivity.

Low

Relies on yfinance — unofficial Yahoo Finance data

yfinance is an unofficial library that scrapes Yahoo Finance APIs. Data may be delayed, incomplete, or break without notice. The skill acknowledges NAV timing limitations and 15-minute price delays in its caveats.

Sources and relations

Context around this Skill.

Repository

himself65/finance-skills

topic

ETF premium & discount analysis

topic

Gamma squeeze & dealer hedging

topic

Options flow & GEX

agent

Claude Code

collection

Market analysis

guide

Reviewing finance skills before install

Registry

Read this record as data.

The public record includes the page-safe snapshot, evidence, assessment, taxonomy, and relations. Internal revision fields stay outside the public projection.

Record ID
github:himself65/finance-skills:plugins/market-analysis/skills/etf-premium
Snapshot ID
fsh-etf-premium-2026-07-29-001
This page is an informational registry entry, not investment advice or a security guarantee. A high content quality score does not make the Skill safe for every environment. Review current files, permissions, data sources, and financial assumptions before use.