Stock Analysis

Stock Analysis

Comprehensive stock research with a data-driven Buy / Hold / Sell signal. Works immediately with no API key — add a free Alpha Vantage key to unlock technical indicators.

When to Use

• "Analyze AAPL", "What's the outlook for Tesla?", "Should I buy Microsoft?"
• "Is Nvidia overvalued?", "Is TSLA overbought right now?"
• Quick price check: "What is Amazon trading at?"
• Comparing two stocks: "AAPL vs MSFT — which looks stronger?"
• Pre-earnings or macro research on any public company

Quick Reference

Procedure

Step 1 — Run the analysis

Always start with the helper script. It runs four phases automatically:

Without Alpha Vantage key (price + fundamentals only):

python scripts/analyze_stock.py {TICKER}

With Alpha Vantage key (full analysis including technicals):

python scripts/analyze_stock.py {TICKER} --av-key $ALPHA_VANTAGE_API_KEY

The four phases:

1. Quote — current price, day change %, volume vs average, 52-week range
2. Fundamentals — P/E ratio, EPS, market cap, analyst consensus target and rating
3. Technicals — RSI-14, MACD crossover signal, price vs SMA-50 (requires Alpha Vantage key)
4. Signal — each metric casts a vote → BUY / HOLD / SELL with score and reasoning

Step 2 — Interpret the signal

After the script runs, present the output and add brief commentary:

• BUY (score ≥ +2): Which metrics are driving it? A score of +4 or +5 is a strong signal; +2 is marginal — note the risks.
• SELL (score ≤ -2): Is this overvaluation, technical breakdown, or both? Note if the analyst target disagrees.
• HOLD (-1 to +1): Explain the tension — e.g. strong momentum but rich valuation, or cheap stock with deteriorating technicals.

Always close with: "This is quantitative analysis based on current data, not financial advice."

Step 3 — Offer follow-up

After presenting the signal, offer:

• Compare a peer: run the same analysis on a direct competitor (e.g. for AAPL → MSFT or GOOGL)
• Sector context: note where P/E sits relative to the industry (tech typically 20–40; value stocks typically 10–20)
• 52-week context: the bar chart in the output shows exactly where in its range the stock sits

Scoring Logic

Each metric votes -1 / 0 / +1:

Signal thresholds: Sum ≥ +2 → BUY | -1 to +1 → HOLD | ≤ -2 → SELL

Without an Alpha Vantage key only 2 metrics vote (P/E and analyst target), so maximum score is ±2.

Pitfalls

• Yahoo Finance rate limits: If you get empty results or a 429 error, wait 30 seconds and retry. The script sends a browser User-Agent to reduce this.
• Ticker not found: Use the exchange-qualified format if needed — BRK-B not BRK.B, 0700.HK for Hong Kong stocks.
• P/E not available: Negative earnings stocks (early-stage, biotech) have no P/E — the metric is skipped rather than penalized.
• Alpha Vantage free tier: 25 API calls/day. Each full analysis uses 3 calls (RSI + MACD + SMA). Don't run more than 8 full analyses per day on the free key.
• Pre-market / after-hours: Yahoo Finance returns the last regular session price. If the user asks during extended hours, note this caveat.
• Non-US stocks: Yahoo Finance supports most global exchanges. Use the local ticker format (e.g. ASML.AS for Euronext Amsterdam).

Verification

The analysis completed successfully if:

• A price displays with a today % change
• The 52-week range bar chart brackets the current price
• SIGNAL VOTES section shows at least 2 metrics
• Output ends with BUY / HOLD / SELL and a one-line reasoning summary

Rate Limits