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Added P/E & PEG valuation indicators

Ticket #275: Adding P/E and PEG valuation indicators (high and low)
Type: Feature / Decision Support / Business Analysis
Affected Component: code_source_simule/portfolio_metrics.py, code_source_simule/flask_app.py, code_source_simule/tooltip_guidance.py, templates/dashboard.html, templates/demo_index.html, tests/test_portfolio_metrics.py, tests/test_dashboard.py, tests/test_tooltip_guidance_contract.py, tests/conftest.py, data_fixtures/pe_ratio_indicators.csv, data_fixtures/peg_ratio_indicators.csv, docs/features/chapter4.md, docs/fr/features/chapter4.md, specs/017-global-quality-indicators/

1. Context

This implementation extends my two latest interventions: adding portfolio management-rule indicators, then adding analyst signals. The logic remains the same: turn the dashboard into a real decision-support tool and prepare a clear information base for future advisory AI (see my Project Vision).

This time, I focused on a missing decision angle: valuation through two complementary ratios, P/E (price vs earnings) and PEG (price vs earnings adjusted for expected growth). Both are central in my investment strategy, but neither was visible in a concise and actionable format on dashboard and demo.

2. Objective

Make the most expensive and least expensive portfolio valuations immediately readable, under both price/earnings (P/E) and price/growth (PEG) perspectives, so extreme cases can be spotted at a glance.

Concretely, the goal was to:

  • surface the ten highest-P/E titles and the ten lowest-P/E titles;
  • surface the ten highest-PEG titles and the ten lowest-PEG titles;
  • display each row with ticker and current ratio in a clean, comparable format;
  • keep the exact visual language of existing performer cards for frictionless reading.

3. What was delivered

  • Four new valuation indicators delivered in parallel on /dashboard and /demo:
    • Highest P/E Ratio: the ten titles with the highest P/E, sorted from highest to lowest.
    • Lowest P/E Ratio: the ten titles with the lowest P/E, sorted from lowest to highest.
    • Highest PEG Ratio: the ten titles with the highest PEG, sorted from highest to lowest.
    • Lowest PEG Ratio: the ten titles with the lowest PEG, sorted from lowest to highest.
  • A clear and disciplined presentation:
    • each row displays ticker and ratio (P/E or PEG) with two decimals;
    • deterministic ordering: when values are equal, rows are tie-broken by ticker A-Z;
    • explicit empty-state message per card when no title is eligible.
  • A deliberately strict inclusion rule: only titles with numeric, strictly positive ratios are included, since null, negative, or non-usable values are not comparable for valuation reading.
  • An autonomous calculation scope: indicators rely strictly on current CSV data and keep the latest available value per ticker, without external market dependencies.
  • Strict visual consistency: P/E and PEG cards reuse the structure and styles of the existing "Top / Flop Performers" blocks.
  • Stronger educational consistency: PEG tooltips were integrated into the same business contract as existing metric tooltips, with direct anchors to chapter 4 strategy documentation.

4. Business impact

  • Immediate valuation visibility, from two angles: P/E and PEG extremes are identifiable instantly, without manual sorting.
  • Better decision support: the P/E + PEG pair helps distinguish a simply expensive valuation from an expensive valuation that may still be justified by growth.
  • Vision continuity: this addition complements previous indicators and enriches the context future advisory AI can use.
  • Signal reliability: strict filtering of non-usable P/E and PEG values improves decision-time signal quality.

5. Validation and status

  • Focused feature test suite green: 71 passed.
  • Key behaviors covered with dedicated tests: filtering missing/non-numeric/non-positive P/E and PEG values, descending and ascending ordering per card, A-Z tie-break under equal values, two-decimal display formatting, explicit empty states, and visual parity with reference cards.
  • Tooltip contract validated: new P/E and PEG keys are present, anchors are coherent, and fallback messaging remains robust.
  • Non-regression confirmed: existing performer cards remain intact after adding all four valuation cards.
  • Related traceability issue: #275.

6. Lessons learned

  1. Reusing an already familiar visual language accelerates delivery and lowers cognitive load: users immediately understand new cards, even when a second ratio family is added.
  2. A clear inclusion filter (strictly positive ratios only) is better than exhaustive display: a precise signal beats noisy completeness.
  3. Delivering P/E and PEG together improves decision quality: P/E shows raw valuation tension, while PEG puts that tension in perspective with expected growth.
  4. Token usage summary: For this combined delivery of P/E and PEG valuation indicators, the gross consumption recorded is $13.69 for 1360.6 Copilot AI credits. Compared to similar recent implementations mentioned in the Context section above, this third delivery costs approximately 22.45% more than the second delivery but 16.88% less than the first delivery. This increase compared to the previous delivery can be explained by the scope of the current implementation: 4 indicators added today VS 3 previously.