margin-management（保证金管理）

Margin Management

Purpose

Monitor and manage margin-living strategy by tracking margin balances, interest costs, dividend coverage ratios, and portfolio-to-margin safety thresholds. Provides data-driven scaling recommendations based on strategy milestones.

When to Use

Use this skill when:

• Importing new Fidelity balances CSV
• Updating margin balance or interest rate
• Calculating coverage ratio (dividends ÷ interest)
• User mentions: "margin dashboard", "margin balance", "coverage ratio", "margin strategy"
• Assessing margin scaling decisions
• Checking safety thresholds

Core Workflow

1. Read Fidelity Balances CSV

Location: notebooks/updates/Balances_for_Account_{account_id}.csv

Key Fields to Extract:

Balance,Day change
Total account value,228809.41,3447.61      → Portfolio Value
Margin buying power,193919.92,-4667.04
Net debit,-2992.70,-2191.14                 → Margin Balance (abs value)
Margin interest accrued this month,1.12,    → Monthly Interest (actual)

Calculations:

• Margin Balance: Absolute value of "Net debit" = $2,992.70
• Interest Rate: Default 10.875% (Fidelity $1k-$24.9k tier) unless specified
• Monthly Interest Cost: Balance × Rate ÷ 12 = $2,992.70 × 0.10875 ÷ 12 = $27.11

2. Safety Check: Margin Jump Alert

Rule: If new margin balance > previous balance + $5,000, STOP

Reason: Large draws should be intentional per margin-living strategy

Example:

Previous: $2,992.70
Current: $9,500.00 (+$6,507.30) → 🚨 ALERT - Confirm intentional draw

Action:

• Alert user immediately
• Show diff: "Margin increased by $6,507 - Confirm this was intentional"
• Wait for user confirmation before proceeding

3. Add Entry to Margin Dashboard

Insert new row with:

• Date: Current date (use date +"%Y-%m-%d")
• Margin Balance: From Balances CSV (Net debit absolute value)
• Interest Rate: 10.875% (or updated rate from CSV if available)
• Monthly Interest Cost: Calculate (Balance × Rate ÷ 12)
• Notes: Auto-generate based on elapsed time since Oct 9, 2025

Example Entry:

Date: 2025-11-11
Margin Balance: $2,992.70
Interest Rate: 10.875%
Monthly Interest Cost: $27.11
Notes: Month 1 - Building foundation, on track per strategy

Notes Generation Logic:

months_elapsed = (current_date - datetime(2025, 10, 9)).days // 30

if months_elapsed < 6:
    note = f"Month {months_elapsed} - Building foundation, on track per strategy"
elif months_elapsed < 12:
    note = f"Month {months_elapsed} - Approaching Month 6 milestone"
elif months_elapsed < 18:
    note = f"Month {months_elapsed} - Approaching break-even milestone"
else:
    note = f"Month {months_elapsed} - Mature strategy, monitor scaling"

4. Update Summary Section

Recalculate Dashboard Metrics:

Current Margin Balance

= Latest entry from Margin Dashboard
Example: $2,992.70

Monthly Interest Cost

= Latest calculated cost
Example: $27.11/month

Annual Interest Cost

= Monthly Interest Cost × 12
Example: $27.11 × 12 = $325.32/year

Dividend Income (from Dividend Tracker)

= Pull from Dividend Tracker "TOTAL EXPECTED DIVIDENDS"
Example: $2,847.32/month

Coverage Ratio

= Dividend Income ÷ Monthly Interest Cost
Formula: =IFERROR(Dividends / Interest, 0)
Example: $2,847.32 ÷ $27.11 = 105.0x 🟢

Fix #DIV/0! if margin balance = $0:

Before: =B10 / B11  (causes #DIV/0! when margin = 0)
After: =IFERROR(B10 / B11, 0)  (returns 0 when no margin)

5. Calculate Strategy Metrics

Portfolio-to-Margin Ratio

= Total account value ÷ Margin Balance
Example: $228,809.41 ÷ $2,992.70 = 76.5:1 🟢🟢🟢

Safety Thresholds:

• 🟢 Green: Ratio > 4.0:1 (target - healthy margin usage)
• 🟡 Yellow: Ratio 3.5-4.0:1 (warning - pause scaling)
• 🔴 Red: Ratio < 3.0:1 (alert - stop draws, inject business income)
• ⚫ Critical: Ratio < 2.5:1 (emergency - inject $30k+, consider selling)

Current Draw vs Fixed Expenses

Current monthly draw: $4,500 (fixed expenses only)
Target: Start with $4,500, scale to $6,213, $8,000, $10,000 based on data

6. Scaling Alerts (Time-Based)

Strategy Start Date: October 9, 2025

Calculate months elapsed:

from datetime import datetime
start = datetime(2025, 10, 9)
current = datetime.now()
months_elapsed = (current - start).days // 30

Month 6 Alert (April 2026)

📊 MONTH 6 MILESTONE CHECK:
✅ Dividends: $2,847/month (need $2,000+)
✅ Portfolio-to-Margin Ratio: 76.5:1 (need 4:1+)
✅ Dividend Growth: On track

🎯 RECOMMENDATION: Scale margin draw to $6,213/month (add mortgage)
- Current: $4,500 (fixed expenses only)
- New: $6,213 (fixed + mortgage)
- Safety margin: Excellent

Month 12 Alert (October 2026)

📊 MONTH 12 BREAK-EVEN CHECK:
Expected Dividends: $4,500+/month (goal: break-even with margin interest)
✅ IF achieved: Consider scaling to $8,000/month (add some variable expenses)
⚠️ IF not: Hold at $6,213, assess strategy

Month 18 Alert (April 2027)

📊 MONTH 18 MATURE STRATEGY CHECK:
Expected Dividends: $7,000+/month
Expected Margin: Declining (dividends paying down debt)
✅ IF achieved: Consider scaling to $10,000/month (most variable expenses)
⚠️ IF not: Hold current level, reassess timeline

7. Alert Thresholds

Generate alerts based on conditions:

Green (Healthy)

✅ Ratio > 4:1 AND dividends covering interest
Status: On track, continue per strategy

Yellow (Caution)

⚠️ Ratio 3.5-4:1 OR dividend coverage declining
Action: Pause scaling, monitor weekly

Red (Alert)

🚨 Ratio < 3:1 OR dividend cuts detected
Action: STOP draws, inject $20k business income

Critical (Emergency)

⛔ Ratio < 2.5:1 OR margin call risk
Action: STOP draws, inject $30k+ business income, consider selling hedge (SQQQ)

Critical Rules

WRITABLE Columns (Margin Dashboard)

• ✅ Date (Column A)
• ✅ Margin Balance (Column B)
• ✅ Interest Rate (Column C)
• ✅ Monthly Interest Cost (Column D - calculated but writeable)
• ✅ Notes (Column E)

SACRED Formulas (NEVER TOUCH)

• ❌ Coverage Ratio (unless adding IFERROR wrapper)
• ❌ Summary section totals (unless fixing #DIV/0!)

Margin Strategy Philosophy

Core Principle: Confidence-based scaling, not time-based mandates

Decision Framework:

1. Data-driven: Decisions backed by actual dividend income, not projections
2. Safety-first: Never scale if ratio drops below 3.5:1
3. Business income as insurance: Available $22k/month, not primary strategy
4. Monte Carlo backstop: 98.5% of scenarios used business income at some point

Business Income Backstop

Available: $22,000/month from business operations

Usage Scenarios:

1. ⛔ Margin call (ratio < 3:1): MUST USE business income immediately
2. ⚠️ Market correction (20-30% drop): OPTIONAL - assess need
3. 🎯 Acceleration (reach FI faster): OPTIONAL - strategic choice

Current Philosophy: Insurance policy only, not active strategy component

Example Calculations

Scenario 1: Month 1 (Current State)

Portfolio Value: $228,809.41
Margin Balance: $2,992.70
Ratio: 76.5:1 🟢🟢🟢

Monthly Interest: $27.11
Dividend Income: $2,847.32
Coverage: 105.0x 🟢

Status: Excellent - building foundation

Scenario 2: Month 6 (Projected)

Portfolio Value: $280,000 (projected with W2 contributions)
Margin Balance: $25,000 (scaled to $6,213/month draw)
Ratio: 11.2:1 🟢

Monthly Interest: $227
Dividend Income: $4,500 (projected)
Coverage: 19.8x 🟢

Status: Healthy - on track for break-even

Scenario 3: Month 15 (Break-Even)

Portfolio Value: $350,000
Margin Balance: $50,000 (scaled to $8,000/month draw)
Ratio: 7.0:1 🟢

Monthly Interest: $453
Dividend Income: $6,800
Coverage: 15.0x 🟢

Status: Break-even achieved, dividends > interest

Google Sheets Integration

Spreadsheet ID: Read from fin-guru/data/user-profile.yaml → google_sheets.portfolio_tracker.spreadsheet_id

Use the mcp__gdrive__sheets tool:

// STEP 1: Read Spreadsheet ID from user profile
// Load fin-guru/data/user-profile.yaml
// Extract: google_sheets.portfolio_tracker.spreadsheet_id

// STEP 2: Read Margin Dashboard
mcp__gdrive__sheets(
    operation: "spreadsheets.values.get",
    params: {
        spreadsheetId: SPREADSHEET_ID,  // from user-profile.yaml
        range: "Margin Dashboard!A2:E50"
    }
)

// STEP 3: Add new margin entry
mcp__gdrive__sheets(
    operation: "spreadsheets.values.update",
    params: {
        spreadsheetId: SPREADSHEET_ID,  // from user-profile.yaml
        range: "Margin Dashboard!A2:E2",
        valueInputOption: "USER_ENTERED",
        requestBody: {
            values: [[date, balance, rate, monthly_cost, notes]]
        }
    }
)

Agent Permissions

Margin Specialist (Write-enabled):

• Can add new entries to Margin Dashboard
• Can update margin balance, rate, cost
• Can generate scaling alerts
• CANNOT modify summary formulas (without formula-protection skill)

Builder (Write-enabled):

• Can repair broken formulas (#DIV/0!)
• Can update summary section calculations
• Can add new metrics

All Other Agents (Read-only):

• Market Researcher, Quant Analyst, Strategy Advisor
• Can read margin data for analysis
• Cannot write to spreadsheet
• Must defer to Margin Specialist or Builder

Reference Files

For complete strategy details, see:

• Margin Strategy: fin-guru-private/fin-guru/strategies/active/margin-living-master-strategy.md
• Portfolio Strategy: fin-guru-private/fin-guru/strategies/active/portfolio-master-strategy.md
• User Profile: fin-guru/data/user-profile.yaml
• Spreadsheet Architecture: fin-guru/data/spreadsheet-architecture.md

Pre-Flight Checklist

Before updating Margin Dashboard:

• Fidelity Balances CSV is latest by date
• CSV is in notebooks/updates/ directory
• Margin Dashboard sheet exists in Google Sheets
• Previous margin balance known (for jump detection)
• Dividend Tracker is up-to-date (for coverage ratio)
• Current date retrieved via date command

Example Scenario

Trigger: User downloads new Fidelity balances CSV

Agent workflow:

1. ✅ Read Balances CSV - Portfolio: $228,809.41, Margin: $2,992.70
2. ✅ Safety check - Previous: $0, Current: $2,992.70 (+$2,992.70 < $5k threshold) - PASS
3. ✅ Calculate metrics:

- Monthly interest: $27.11 - Portfolio-to-margin ratio: 76.5:1 - Coverage ratio: 105.0x (dividends ÷ interest)

1. ✅ Add entry to Margin Dashboard:

- Date: 2025-11-11 - Balance: $2,992.70 - Rate: 10.875% - Cost: $27.11 - Notes: "Month 1 - Building foundation, on track"

1. ✅ Update summary section:

- Current balance: $2,992.70 - Monthly cost: $27.11 - Annual cost: $325.32 - Dividend income: $2,847.32 - Coverage: 105.0x

1. ✅ Generate status: "🟢 Excellent health - Ratio 76.5:1, Coverage 105x"
2. ✅ LOG: "Updated Margin Dashboard - Month 1, $2,992.70 balance, 76.5:1 ratio"

Skill Type: Domain (workflow guidance) Enforcement: BLOCK (financial risk critical) Priority: Critical Line Count: < 400 (following 500-line rule) ✅