ADR / H-Share / A-Share Cross-Listing Analysis

def calculate_ah_premium(a_price_cny, h_price_hkd, usdcny, usdhkd):
    """Calculate AH premium for a dual-listed stock."""
    h_price_cny = h_price_hkd * (usdcny / usdhkd)  # Convert HKD to CNY
    ah_premium = (a_price_cny / h_price_cny - 1) * 100
    return ah_premium

# Example: PetroChina
# A-share: 8.50 CNY, H-share: 6.20 HKD
# USDCNY: 7.25, USDHKD: 7.82
# H in CNY: 6.20 * (7.25/7.82) = 5.75 CNY
# AH Premium: (8.50/5.75 - 1) * 100 = 47.8%

def calculate_adr_premium(adr_price_usd, hk_price_hkd, adr_ratio, usdhkd):
    """
    Calculate ADR premium over HK listing.
    adr_ratio: number of HK shares per 1 ADR (e.g., BABA: 1 ADR = 8 HK shares)
    """
    hk_equivalent_usd = (hk_price_hkd * adr_ratio) / usdhkd
    premium = (adr_price_usd / hk_equivalent_usd - 1) * 100
    return premium

# Example: Alibaba
# BABA ADR: $85.00, 9988.HK: HKD 82.50
# ADR ratio: 1 ADR = 8 HK shares
# HK equivalent: (82.50 * 8) / 7.82 = $84.40
# ADR premium: (85.00/84.40 - 1) * 100 = 0.71%

delisting_risk_factors = {
    "pcaob_status": "inspected",     # inspected / pending / blocked
    "sec_identified_years": 0,        # 0, 1, 2, or 3 (3 = delist)
    "has_hk_listing": True,           # Backup listing reduces impact
    "hk_listing_type": "primary",     # primary (can be in Connect) vs secondary
    "vie_structure": True,            # Variable Interest Entity adds legal risk
    "state_owned": False,             # SOE status adds geopolitical risk
}

# Companies with HK primary listing (BABA, JD, BIDU, NTES, etc.) have
# a safety net if US delisting occurs → fungible conversion ADR → HK shares
# Companies with US-only listing (PDD until HK listing) face higher risk

# When AH premium for a specific stock diverges significantly from its historical average
ah_premium_current = 45  # current premium
ah_premium_mean_12m = 35  # 12-month average
ah_premium_std = 8        # standard deviation

z_score = (ah_premium_current - ah_premium_mean_12m) / ah_premium_std

if z_score > 2.0:
    signal = "fade_premium"  # A-share overvalued vs H; buy H, avoid A
elif z_score < -2.0:
    signal = "buy_premium"   # A-share undervalued vs H; buy A, avoid H
else:
    signal = "neutral"

import yfinance as yf

# Fetch ADR and HK prices simultaneously
baba_adr = yf.download("BABA", start="2025-01-01", end="2026-03-30", progress=False)
baba_hk = yf.download("9988.HK", start="2025-01-01", end="2026-03-30", progress=False)

# For A+H pairs
petrochina_a = yf.download("601857.SS", start="2025-01-01", end="2026-03-30", progress=False)
petrochina_h = yf.download("0857.HK", start="2025-01-01", end="2026-03-30", progress=False)

# FX rates for premium calculation
cny = yf.download("CNY=X", start="2025-01-01", end="2026-03-30", progress=False)  # USD/CNY
hkd = yf.download("HKD=X", start="2025-01-01", end="2026-03-30", progress=False)  # USD/HKD

# AH Premium Index (HSAHP)
# Not directly on yfinance; use Hang Seng website or Tushare

## Cross-Listing Analysis — [Company Name]

### Listing Structure
- **A-share**: [code] @ [price CNY]
- **H-share**: [code] @ [price HKD]
- **ADR**: [ticker] @ [price USD] (ratio: X HK shares = 1 ADR)

### Premium/Discount
- **AH Premium**: [X%] (12m avg: X%, z-score: X.X)
- **ADR-HK Premium**: [X%] (5d avg: X%)
- **Direction**: [AH premium widening / narrowing / stable]

### Valuation Comparison
| Metric | A-share | H-share | ADR |
|--------|---------|---------|-----|
| PE (TTM) | XX.X | XX.X | XX.X |
| PB | X.X | X.X | X.X |
| Dividend yield | X.X% | X.X% | X.X% |

### Delisting Risk (ADR)
- **PCAOB status**: [inspected / pending]
- **SEC identified years**: [0/1/2/3]
- **HK backup**: [yes-primary / yes-secondary / no]
- **Risk level**: [low / medium / high / critical]

### Arbitrage Signal
- **AH premium z-score**: [X.X] → [fade premium / neutral / buy premium]
- **Best market to buy**: [A / H / ADR] — rationale
- **Catalyst**: [index inclusion, Connect eligibility, earnings]

### Investment Implication
- **Preferred listing**: [H-share / ADR / A-share] for new position
- **Risk**: [delisting, FX, regulatory, liquidity]