fund-vehicles
Compare and select investment vehicles including mutual funds, ETFs, index funds, and separately managed accounts. Use when the user asks about ETF vs mutual fund, expense ratios, fund tax efficiency, ETF creation/redemption, tracking error, or share class comparisons. Also trigger when users mention 'which fund should I buy', 'Vanguard vs Fidelity', 'index fund costs', '12b-1 fees', 'load vs no-load', 'SMA vs ETF', 'fund turnover ratio', 'securities lending', or ask how fees compound over time.
- Installs
- 699
- Last 24h
- —
- Trending rank
- —
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://github.com/joellewis/finance_skills --skill fund-vehicles- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads fund-vehicles automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
Fund Vehicles
Core Concepts
Vehicle Comparison: Decision-Relevant Differences
- Trading: ETFs trade intraday at market prices that can deviate from NAV (premiums/discounts, especially in volatile markets or for illiquid underlying assets); mutual funds transact once daily at NAV.
- Tax efficiency: ETFs generally distribute far fewer capital gains than mutual funds (mechanism below); SMAs allow lot-level tax-loss harvesting that pooled vehicles cannot.
- Customization: SMAs hold individual securities directly, so investors can exclude stocks/sectors and harvest specific lots; minimums are typically $100K-$1M+ with fees above index ETFs.
- Cost: broad index ETFs and index mutual funds cost as little as 0.01-0.05%; active mutual funds commonly cost 0.50-1.00%+ before any loads.
Expense Ratios
Total annual cost as a percentage of AUM, deducted from fund returns. Includes management fees, administrative costs, and sometimes 12b-1 distribution fees. The expense ratio is the single most predictive factor of future fund performance — lower-cost funds consistently outperform higher-cost funds within the same category.
Tracking Difference
The actual return gap between a fund and its benchmark index over a period. Tracking difference = Fund Return - Index Return. Expense ratio is a floor for tracking difference, but additional factors (securities lending income, sampling, cash drag, trading costs) can make tracking difference better or worse than the expense ratio.
Tax Efficiency and the Creation/Redemption Mechanism
The general tax-efficiency hierarchy: ETFs > index mutual funds > actively managed mutual funds.
Authorized Participants (APs) create ETF shares by delivering a basket of the underlying securities in-kind, and redeem by receiving securities in-kind. These in-kind transfers do not trigger capital gains, so ETFs rarely distribute gains. Mutual funds must sell securities to meet redemptions, distributing the resulting gains to all remaining shareholders — taxable events even for buy-and-hold investors.
Securities Lending Revenue
Funds can lend their holdings to short sellers in exchange for a fee. This revenue can partially or fully offset fund expenses, sometimes resulting in tracking difference better than the expense ratio. Large index funds are major securities lenders.
Turnover Ratio
Measures how frequently a fund buys and sells its holdings. Higher turnover leads to more taxable capital gains distributions, higher transaction costs, and greater market impact. Typical turnover: index funds 3-10%, active funds 50-200%+.
12b-1 Fees and Loads
- 12b-1 fees: annual distribution and marketing fees (0.25-1.0%), included in the expense ratio.
- Front-end loads: one-time sales charge at purchase (typically 3-5.75%), reducing the initial investment.
- Back-end loads (CDSCs): Contingent Deferred Sales Charges paid upon redemption, typically declining to 0% over 5-7 years.
Key Formulas
| Formula | Expression | Use Case |
|---|---|---|
| Expense Drag (annual) | AUM × Expense Ratio | Annual cost of fund ownership |
| Tracking Difference | Fund Return - Index Return | Actual cost of indexing |
| Fee Impact (compounded) | FV = PV × (1 + r - ER)^n vs PV × (1 + r)^n | Long-term fee drag |
| Tax Cost Ratio | Pre-Tax Return - After-Tax Return | Tax efficiency measure |
| NAV | (Total Assets - Liabilities) / Shares Outstanding | Fund share value |
Worked Examples
Example 1: Long-Term Fee Impact
Given: $100,000 invested for 30 years at 8% gross return. Fund A: 0.03% expense ratio. Fund B: 0.75% expense ratio. Calculate: Final values and fee drag for each fund Solution: Fund A: $100,000 × (1 + 0.08 - 0.0003)^30 = $100,000 × (1.0797)^30 = $997,914 Fund B: $100,000 × (1 + 0.08 - 0.0075)^30 = $100,000 × (1.0725)^30 = $816,430 Difference: $997,914 - $816,430 = $181,484
The 0.72% annual fee difference (0.75% - 0.03%) compounds to $181,484 over 30 years — approximately 18% of the low-cost fund's terminal value. This is wealth destroyed by fees for an identical gross return.
Example 2: ETF vs Mutual Fund Tax Efficiency
Given: Identical S&P 500 portfolios, $100,000 invested for 20 years. Gross return 10%, expense ratio 0.03% for both, so both grow at 9.97% before distribution taxes. The ETF distributes $0 in capital gains (in-kind redemptions). The mutual fund distributes 2% of NAV in long-term capital gains each year-end. The investor is in the 20% LTCG bracket.
Assumptions: Distributions are taxed at 20% in the year received; the after-tax remainder is reinvested and adds to cost basis. Both positions are liquidated after year 20, with remaining unrealized gains taxed at 20%.
Calculate: After-tax liquidation values Solution:
ETF — all gains deferred until sale:
- Pre-tax terminal value: $100,000 × (1.0997)^20 = $669,090
- Liquidation tax: ($669,090 - $100,000) × 20% = $113,818
- After-tax value: $555,272
Mutual fund — year-by-year, each year the position grows 9.97%, distributes 2% of NAV, and pays 20% tax on the distribution (equivalent to multiplying by 1.0997 × 0.996 each year):
- Pre-liquidation value after 20 years: $617,549
- Taxes paid on distributions along the way: $23,888 (on $119,442 of cumulative distributions)
- Cost basis: $100,000 + $95,554 reinvested after-tax distributions = $195,554
- Liquidation tax: ($617,549 - $195,554) × 20% = $84,399
- After-tax value: $617,549 - $84,399 = $533,150
The ETF's tax deferral advantage is $555,272 - $533,150 = $22,122 over 20 years on this $100,000 investment — the cost of paying tax annually instead of letting the full balance compound until sale.
Common Pitfalls
- Ignoring tracking difference — it can be worse than the expense ratio due to cash drag, sampling, and trading costs
- Not considering tax efficiency when comparing returns — pre-tax fund returns overstate what taxable investors actually keep
- Confusing NAV with market price for ETFs — ETFs can trade at premiums or discounts to NAV, especially in volatile markets or for illiquid underlying assets
- Overlooking securities lending income that offsets expenses — some index funds achieve tracking difference better than their expense ratio
Cross-References
- equities (wealth-management plugin): equity fund selection and equity index tracking
- fixed-income-sovereign (wealth-management plugin): bond fund considerations (see also fixed-income-corporate (wealth-management plugin))
- tax-efficiency (wealth-management plugin): comprehensive after-tax investment analysis
- asset-allocation (wealth-management plugin): selecting vehicles within an asset allocation
- factor-investing (wealth-management plugin): evaluating factor ETFs and smart-beta funds on factor purity, turnover, capacity, and fee per unit of loading
Running the script
uv run scripts/fund_vehicles.py
The PEP 723 header resolves the numpy dependency automatically. Alternatively run python3 scripts/fund_vehicles.py after pip install numpy.
- Bare run prints a demo covering fee impact, tracking error, NAV premium/discount, fund overlap, and ETF-vs-mutual-fund tax efficiency.
--verifyre-runs the demo computations and asserts the outputs match this skill's worked examples (prints PASS/FAIL, nonzero exit on mismatch).--helplists the available classes.
The file is primarily meant to be imported as a module, e.g. from fund_vehicles import ExpenseAnalysis, TrackingAnalysis, TaxEfficiency.
FAQ
What does the fund-vehicles skill do?
Compare and select investment vehicles including mutual funds, ETFs, index funds, and separately managed accounts. Use when the user asks about ETF vs mutual fund, expense ratios, fund tax efficiency, ETF creation/redemption, tracking error, or share class comparisons. Also trigger when users mention 'which fund should I buy', 'Vanguard vs Fidelity', 'index fund costs', '12b-1 fees', 'load vs no-load', 'SMA vs ETF', 'fund turnover ratio', 'securities lending', or ask how fees compound over time.
How do I install fund-vehicles?
Run npx skills add https://github.com/joellewis/finance_skills --skill fund-vehicles in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/fund-vehicles/ (personal) or .claude/skills/fund-vehicles/ (project).
Which AI agents can use fund-vehicles?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is fund-vehicles safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains fund-vehicles?
It is published by joellewis in joellewis/finance_skills. It has 699 recorded installs.
More from joellewis/finance_skills
asset-allocation
joellewis/finance_skills
Determine how to distribute capital across asset classes using strategic and tactical allocation frameworks. Use when the user asks about portfolio allocation, mean-variance optimization, Black-Litterman, risk parity, glide paths, or target-date strategies. Also trigger when users mention 'how much in stocks vs bonds', '60/40 portfolio', 'policy portfolio', 'core-satellite', 'liability-driven investing', 'asset-liability matching', or ask how to split their money across investments.
statistics-fundamentals
joellewis/finance_skills
Apply statistical methods to financial data including descriptive statistics, covariance estimation, regression, hypothesis testing, and resampling. Use when the user asks about return distributions, correlation between assets, building a covariance matrix, running a CAPM regression, testing whether alpha is significant, checking if returns are normal, or estimating confidence intervals. Also trigger when users mention 'volatility', 'how correlated are these', 'fat tails', 'skewness', 'R-squared', 'beta of a fund', 'bootstrap a Sharpe ratio', 'shrinkage estimator', 'Ledoit-Wolf', or ask why their optimizer produces unstable weights.
quantitative-valuation
joellewis/finance_skills
Estimate intrinsic value of stocks and companies using DCF, dividend discount models, comparable multiples, and residual income. Use when the user asks about discounted cash flow, DCF models, WACC, terminal value, dividend discount models, comparable multiples, or sum-of-the-parts valuation. Also trigger when users mention 'what is this stock worth', 'fair value estimate', 'Gordon growth model', 'free cash flow valuation', 'cost of equity', 'sensitivity analysis', 'exit multiple', or ask whether a stock is overvalued or undervalued.
finance-psychology
joellewis/finance_skills
Recognize and mitigate cognitive biases that impair financial decisions, and coach clients toward values-driven financial lives. Use when the user asks about behavioral finance, money psychology, loss aversion, overconfidence, herd behavior, or emotional investing. Also trigger when users mention 'why do I panic sell', 'money fights with my spouse', 'I can never save enough', 'fear of investing', 'lifestyle creep', 'keeping up with the Joneses', 'Rich Life', 'money scripts', or ask how emotions affect financial decisions.
commodities
joellewis/finance_skills
Analyze commodity markets including futures curve dynamics, roll yield, and supply/demand fundamentals. Use when the user asks about commodity investing, commodity ETFs, contango, backwardation, roll yield, commodity indices (GSCI, BCOM), or commodities as an inflation hedge. Also trigger when users mention 'oil prices', 'gold as a safe haven', 'agricultural futures', 'convenience yield', 'storage costs', 'natural gas', 'copper demand', or ask why commodity ETF returns differ from spot price changes.
investment-policy
joellewis/finance_skills
Construct comprehensive Investment Policy Statements governing return objectives, risk tolerance, and portfolio constraints. Use when the user asks about building an IPS, setting return objectives, assessing risk tolerance, defining investment constraints, or establishing rebalancing and benchmark policies. Also trigger when users mention 'investment plan', 'policy portfolio', 'risk capacity vs willingness', 'spending rate for an endowment', 'foundation payout', 'manager selection criteria', or ask how to document their investment strategy.
Popular business & finance skills
sales-enablement
coreyhaines31/marketingskills
When the user wants to create sales collateral, pitch decks, one-pagers, objection handling docs, or demo scripts. Also use when the user mentions 'sales deck,' 'pitch deck,' 'one-pager,' 'leave-behind,' 'objection handling,' 'deal-specific ROI analysis,' 'demo script,' 'talk track,' 'sales playbook,' 'proposal template,' 'buyer persona card,' 'battle card,' 'battlecard,' 'competitive one-pager,' 'win-loss analysis,' 'why are we losing deals,' 'loss reasons,' 'how do I respond to this objection,' 'prospect just said,' 'help my sales team,' 'sales materials,' or 'what should I give my sales reps,' 'cold call script,' or 'voicemail script.' Use this for any document or asset that helps a sales team close deals. For public competitor comparison pages, see competitors. For running buyer interviews or churn research, see customer-research. For marketing website copy, see copywriting. For cold outreach emails, see cold-email. For the offer being sold (bonuses, guarantees, pricing structure),
revops
coreyhaines31/marketingskills
When the user wants help with revenue operations, lead lifecycle management, or marketing-to-sales handoff processes. Also use when the user mentions 'RevOps,' 'revenue operations,' 'lead scoring,' 'outbound pipeline stages,' 'lead routing,' 'MQL,' 'SQL,' 'pipeline stages,' 'deal desk,' 'CRM automation,' 'marketing-to-sales handoff,' 'data hygiene,' 'leads aren't getting to sales,' 'pipeline management,' 'lead qualification,' or 'when should marketing hand off to sales.' Use this for anything involving the systems and processes that connect marketing to revenue. For cold outreach emails, see cold-email. For email drip campaigns, see emails. For pricing decisions, see pricing.
sales-funnel-blueprint
autonnel/autonnel-skills
Turn an offer into a concrete multi-step sales funnel spec - page-by-page structure, price ladder, copy outline and the metrics each step must hit. Use when asked to build a sales funnel, marketing funnel, landing page flow, lead magnet funnel, webinar funnel, tripwire or VSL funnel, when planning a product launch page flow, or when someone asks "what pages do I need" for selling something online.
pricing
coreyhaines31/marketingskills
When the user wants help with pricing decisions, packaging, or monetization strategy. Also use when the user mentions 'pricing,' 'pricing tiers,' 'freemium,' 'free trial,' 'packaging,' 'price increase,' 'value metric,' 'Van Westendorp,' 'willingness to pay,' 'monetization,' 'how much should I charge,' 'my pricing is wrong,' 'pricing page,' 'annual vs monthly,' 'per seat pricing,' 'should I offer a free plan,' 'pricing page teardown,' 'pricing page audit,' 'is my pricing page AI-readable,' or 'can AI read my pricing.' Use this whenever someone is figuring out what to charge, how to structure their plans, or wants to audit a pricing page (for humans and for the AI agents that shortlist tools). For in-app upgrade screens, see paywalls. For offer construction (bonuses, guarantees, value framing, naming) on services/courses/coaching/high-ticket B2B, see offers.
cross-border-ecommerce
nexscope-ai/ecommerce-skills
Cross-border e-commerce expansion advisor. Scores target markets on 8 weighted dimensions (market size, ecommerce penetration, competition, regulatory complexity, logistics infrastructure, payment ecosystem, cultural distance, IP protection), compares 5 fulfillment models with cost and transit data, provides country-by-country tax/duty compliance guides (EU VAT/IOSS, UK VAT, US sales tax, CA GST, AU GST, JP consumption tax), maps local payment preferences by market, and builds a phased expansion roadmap. No API key required.
pricing-strategy
coreyhaines31/marketingskills
When the user wants help with pricing decisions, packaging, or monetization strategy. Also use when the user mentions 'pricing,' 'pricing tiers,' 'freemium,' 'free trial,' 'packaging,' 'price increase,' 'value metric,' 'Van Westendorp,' 'willingness to pay,' 'monetization,' 'how much should I charge,' 'my pricing is wrong,' 'pricing page,' 'annual vs monthly,' 'per seat pricing,' or 'should I offer a free plan.' Use this whenever someone is figuring out what to charge or how to structure their plans. For in-app upgrade screens, see paywall-upgrade-cro.