market-breadth-analyzer

Measure US equity market breadth using advance/decline lines, percentage of stocks above moving averages, and new highs/lows via the Finskills API.

Security Scan

The skill is internally consistent: it asks for a Finskills API key, calls only Finskills endpoints, and its analysis steps match the stated purpose, with a couple of small documentation mismatches noted below.

Purpose & Capability

Name/description, required env var (FINSKILLS_API_KEY), and the SKILL.md all consistently indicate the skill fetches breadth data from the Finskills API and computes ADR, % above MAs, new highs/lows, short-volume lists, and a composite score. The declared primary credential matches the service used and is proportionate to the stated purpose.

Instruction Scope

Runtime instructions are narrowly scoped to GET requests against https://finskills.net endpoints and local calculations. Minor inconsistencies: the 'Narrowness Index' calculation references constituent weights/leader counts but the documented endpoints do not explicitly provide constituent weights or per-constituent contribution data; the output template includes 'Russell' yet the Market Summary extract only lists S&P 500 and Nasdaq. These appear to be documentation gaps rather than requests for unrelated system data — they may require additional Finskills endpoints or clarification.

Install Mechanism

Instruction-only skill with no install spec and no code files; nothing is downloaded or written to disk by the skill itself according to the provided metadata, which minimizes install-time risk.

Credentials

Only a single credential is required (FINSKILLS_API_KEY), which directly maps to the external API the skill uses. No other environment variables or credential scopes are requested. Note: the API key is a secret and grants Finskills access to requests made by the skill, so treat it as sensitive.

Persistence & Privilege

always:false and no requested config paths or system-level changes. disable-model-invocation:false is the platform default (allows autonomous invocation) and is not in itself a concern. The skill does not request persistent/privileged presence beyond normal operation.

Assessment

This skill appears to do what it says: it needs only a FINSKILLS_API_KEY and will call finskills.net endpoints to compute breadth metrics. Before installing: (1) verify you trust finskills.net and review their API/key management (rotate or limit the key if possible); (2) confirm the Finskills free endpoints actually provide constituent-weight or contribution data if you require the 'Narrowness Index' — otherwise ask the skill author to document which endpoint supplies that data; (3) expect all data requests to go to finskills.net (the API key authorizes those calls), and monitor API usage for unexpected requests. If you need stronger guarantees, request a more detailed endpoint list from the author or restrict the API key scope/usage.

Assess internal market health and regime using breadth indicators from the Finskills API: advance/decline data, percentage of stocks above key moving averages, new highs vs. new lows, and short volume. Identify divergences between index price action and underlying breadth — the most reliable early warning system for market tops and bottoms.

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Setup

API Key required — Register at https://finskills.net to get your free key.
Header: X-API-Key: <your_api_key>

Get your API key: Register at https://finskills.net — free tier available, Pro plan unlocks real-time quotes, history, and financials.

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When to Activate This Skill

Activate when the user:

• Asks "is this rally broad-based or narrow?"
• Wants to assess whether the market is healthy or deteriorating
• Asks about advance/decline ratio, new highs/lows, or breadth divergence
• Wants to understand if it's a good environment to be fully invested
• Asks "are we in a bull or bear market internally?"

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Data Retrieval — Finskills API Calls

1. Market Breadth Indicators

GET https://finskills.net/v1/free/market/breadth

Extract:

• advancers: number of stocks advancing
• decliners: number of stocks declining
• unchanged: number of stocks flat
• new52wHigh: stocks hitting 52-week highs
• new52wLow: stocks hitting 52-week lows
• pctAbove200MA: % of S&P 500 stocks trading above 200-day MA
• pctAbove50MA: % of S&P 500 stocks trading above 50-day MA
• advanceVolume: volume in advancing stocks
• declineVolume: volume in declining stocks

2. Market Summary (Index Price Context)

GET https://finskills.net/v1/market/summary

Extract: S&P 500 and Nasdaq current level, daily change, YTD performance

3. Short Volume (Market Stress Signal)

GET https://finskills.net/v1/free/market/short-volume-top

Extract: list of most heavily shorted stocks today (ratio of short vol to total vol)

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Analysis Workflow

Step 1 — Advance/Decline Analysis

Advance/Decline Ratio (ADR):

ADR = advancers / decliners

ADR	Signal
> 3.0	Strong breadth — broad rally
1.5–3.0	Good breadth — healthy market
0.75–1.5	Mixed breadth — selective market
0.25–0.75	Weak breadth — narrow or declining market
< 0.25	Very weak breadth — broad selloff

Volume-Weighted A/D:

Volume A/D = advanceVolume / declineVolume

If Volume ADR > ADR: Distribution (smart money selling into rally) — bearish signal
If Volume ADR < ADR: Accumulation (buying on pullbacks) — bullish signal

Net New Highs/Lows:

Net New Highs = new52wHigh - new52wLow

• Positive and growing: Strong bull market confirmation
• Negative while index is rising: Breadth divergence ⚠️ (early warning signal)
• Accelerating lows: Risk-off, potential broad decline

Step 2 — Moving Average Participation

Classify market health by % of stocks above key moving averages:

% Stocks Above 200-Day MA:

Level	Market Health
> 70%	Bull market — broad participation
50–70%	Moderate — mixed conditions
30–50%	Weakening — selective market
< 30%	Bear market conditions

% Stocks Above 50-Day MA:

• Leading indicator (shorter-term): signals shifts 2–4 weeks before 200MA
• When 50MA% drops below 40% while 200MA% still > 60%: caution flag ⚠️

Step 3 — Breadth Divergence Detection

Bullish Divergence (oversold bounce setup):

• Index near 52-week lows
• But % stocks above 200MA is rising
• ADR improving → Signal: Internal strength building before price recovers

Bearish Divergence (distribution signal):

• Index near 52-week highs
• But % stocks above 200MA is falling
• New highs count shrinking (fewer stocks making highs)
• Net new lows expanding → Signal: Market becoming a narrow rally — top risk elevated

Participation Narrowing: Calculate the ratio:

Narrowness Index = (leaders outperforming SPY with > 5% weight) / total S&P 500 constituents

If < 10 stocks are driving most of the index return, flag as "narrow rally" with high reversal risk.

Step 4 — Short Volume Stress Signals

Top heavily-shorted stocks signal areas of market stress:

• If heavily shorted stocks are in key sectors: sector under significant bearish pressure
• High short ratio on recent IPOs or hyper-growth names: speculative froth reducing
• Short squeeze potential: stocks with high short ratio + positive news catalyst = snapback risk

Step 5 — Overall Market Health Score

Score each dimension and compute composite:

Dimension	Score (1–5)
ADR (daily)	5=very strong, 1=very weak
NetNewHighs	5=expanding, 1=contracting
% > 200MA	5= > 70%, 1= < 30%
% > 50MA	5= > 65%, 1= < 35%
Vol. A/D Confirm	5=confirmed, 3=neutral, 1=diverging

Market Health Score = avg of 5 dimensions (scale 1–5)

• 4–5: Healthy bull market — stay invested
• 3–4: Moderate — selective stock picking
• 2–3: Weakening — raise cash, reduce risk
• 1–2: Unhealthy — defensive positioning

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Output Format

╔══════════════════════════════════════════════════════╗
║    MARKET BREADTH REPORT  —  {DATE}                 ║
╚══════════════════════════════════════════════════════╝

📊 MARKET INDEXES
  S&P 500:  {level}  {change}%  YTD: {ytd}%
  Nasdaq:   {level}  {change}%  YTD: {ytd}%
  Russell:  {level}  {change}%  YTD: {ytd}%

🩺 MARKET HEALTH SCORE: {X}/5  →  {HEALTHY / MODERATE / WEAKENING / UNHEALTHY}

📈 BREADTH DASHBOARD
  Advancers / Decliners:  {adv} / {dec}  (ADR: {ratio} — {Strong/Weak/Mixed})
  Volume Split:           {adv_vol}B advancing / {dec_vol}B declining
  Volume A/D Ratio:       {ratio} [{Accumulation/Distribution}]

  New 52-Week Highs:  {n}
  New 52-Week Lows:   {n}
  Net New Highs:      {+/-n}  [{Expanding/Contracting}]

  % Stocks > 200-Day MA: {%}  [{Bull/Moderate/Bear} zone]
  % Stocks > 50-Day MA:  {%}

🔍 DIVERGENCE CHECK
  Price vs. Breadth: {No divergence / BULLISH divergence / BEARISH divergence ⚠️}
  Detail: {Brief explanation of any divergence}
  Narrowing Rally Check: {Broad / Narrowing ⚠️}

📊 SHORT INTEREST SIGNALS
  Top Heavily Shorted Stocks Today:
    {TICKER}: {short_ratio}% short volume
    {TICKER}: {short_ratio}% short volume
  Signal: {Normal / Elevated stress in {sector}}

🎯 MARKET HEALTH ASSESSMENT
  Overall Verdict: {Healthy Bull / Mixed / Weakening / Risk-Off}

  Implication for Investors:
    ✅ {What to do if healthy}  OR
    ⚠️ {What to watch / reduce if weakening}

  Key indicator to monitor: {The metric most likely to confirm direction}

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Limitations

• Breadth indicators work best over 5–20 day windows; single-day readings can be noisy.
• % above MA data depends on the data provider's stock universe (may cover S&P 500 constituents only).
• Short volume data from the prior trading day (T+1 reporting lag for official FINRA data).