{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "DerivativeCandidate",
  "type": "object",
  "required": ["underlying", "market", "instrumentType", "direction"],
  "properties": {
    "underlying": {"type": "string"},
    "market": {"type": "string", "enum": ["HK", "US", "AU"]},
    "instrumentType": {"type": "string", "enum": ["CBBC", "WARRANT", "OPTION", "LEAP"]},
    "direction": {"type": "string", "enum": ["bull", "bear", "call", "put", "combo"]},
    "code": {"type": "string"},
    "issuer": {"type": "string"},
    "callLevel": {"type": ["number", "null"]},
    "strike": {"type": ["number", "null"]},
    "expiry": {"type": ["string", "null"], "format": "date"},
    "entitlementRatio": {"type": ["number", "null"]},
    "bid": {"type": ["number", "null"]},
    "ask": {"type": ["number", "null"]},
    "spreadPct": {"type": ["number", "null"]},
    "volume": {"type": ["number", "null"]},
    "turnover": {"type": ["number", "null"]},
    "outstandingPct": {"type": ["number", "null"]},
    "verificationStatus": {"type": "string", "enum": ["unverified", "partial", "verified"]},
    "liquidityRisk": {"type": "string", "enum": ["low", "medium", "high", "critical"]},
    "notes": {"type": "string"}
  }
}