curl --request GET \
  --url https://api.example.com/api/market/v1/list-etf-flows

{
  "timestamp": "<string>",
  "summary": {
    "etfCount": 123,
    "totalVolume": 123,
    "totalEstFlow": 123,
    "netDirection": "<string>",
    "inflowCount": 123,
    "outflowCount": 123
  },
  "etfs": [
    {
      "ticker": "<string>",
      "issuer": "<string>",
      "price": 123,
      "priceChange": 123,
      "volume": 123,
      "avgVolume": 123,
      "volumeRatio": 123,
      "direction": "<string>",
      "estFlow": 123
    }
  ],
  "rateLimited": true
}