Free ETF NAV API
Sources, Fields & Python免费 ETF 净值 API
数据源、字段与 Python 接入

Free ETF NAV API: what developers actually need免费 ETF 净值 API：开发者真正需要什么

ETF NAV data API fields to verifyETF 净值数据接口需要核对的字段

NAV is the per-share value of the fund's net assets at a stated valuation time. An ETF's market price can trade above or below that value, so a generic quote endpoint is not automatically an ETF net asset value API. The U.S. SEC Investor.gov definition of NAV is a useful baseline.

NAV 是基金在指定估值时点的每份净资产价值。ETF 的市场成交价可能高于或低于净值，因此普通行情接口不等于 ETF 净值接口。可参考 美国 SEC Investor.gov 对 NAV 的定义。

The valuation clock matters as much as the number. Official NAV may use closing prices, fair-value adjustments, accrued income and expenses, liabilities, and an official shares-outstanding figure. For international or multi-asset funds, some underlying markets may already be closed when the ETF still trades, so a same-screen comparison can combine observations from different economic times.

估值时钟与数值本身同样重要。官方净值可能使用收盘价格、公允价值调整、应计收入与费用、负债和官方流通份额。国际或多资产基金仍在交易时，部分底层市场可能已经休市，因此同一屏幕上的市场价格与净值可能对应不同经济时点。

Free ETF NAV API sources to evaluate可评估的免费 ETF 净值 API 数据源

Evaluate each source with an ordinary domestic equity ETF, an international ETF whose underlying market closes earlier, a bond fund, a distribution date, a split or share-class event, and a market holiday. Compare value, valuation and publication times, currency, status, revision behavior, and identifier resolution rather than asking only whether a field named nav exists.

可用普通本土股票 ETF、底层市场更早收市的国际 ETF、债券基金、分派日、拆分或份额事件和市场休市日组成测试集。比较数值、估值与发布时间、币种、状态、修订方式和标识解析，而不是只看响应里是否存在名为 nav 的字段。

How to integrate a free historical ETF NAV API如何接入免费的 ETF 历史净值接口

Keep the provider-specific field mapping outside the calculation. After normalizing a response to the keys used below, this example validates the official NAV observation and calculates a premium or discount only when listing, share class, and currency match.

把供应商特定的字段映射与计算逻辑分开。将响应归一化为下面使用的字段后，示例会先验证官方 NAV 观测值；只有上市标的、份额类别和币种一致时，才计算溢价或折价。

from datetime import datetime
from decimal import Decimal, InvalidOperation

import requests


def parse_time(value: str) -> datetime:
    parsed = datetime.fromisoformat(value.replace("Z", "+00:00"))
    if parsed.tzinfo is None:
        raise ValueError("timestamps must include a timezone")
    return parsed


def fetch_json(endpoint: str, params: dict, headers: dict) -> dict:
    response = requests.get(
        endpoint, params=params, headers=headers, timeout=(5, 20)
    )
    response.raise_for_status()
    return response.json()


def premium_discount(nav_row: dict, price_row: dict) -> dict:
    identity = ("fund_id", "share_class", "currency")
    if any(nav_row.get(key) != price_row.get(key) for key in identity):
        raise ValueError("NAV and price identity or currency mismatch")
    if nav_row.get("nav_type") != "official":
        raise ValueError("premium calculation requires official NAV")
    try:
        nav = Decimal(str(nav_row["nav_per_share"]))
        price = Decimal(str(price_row["price"]))
    except (KeyError, InvalidOperation) as exc:
        raise ValueError("invalid NAV or price") from exc
    if nav <= 0 or price <= 0:
        raise ValueError("NAV and price must be positive")

    nav_time = parse_time(nav_row["valuation_time"])
    price_time = parse_time(price_row["observed_at"])
    gap_minutes = abs((price_time - nav_time).total_seconds()) / 60
    return {
        "premium_discount_pct": ((price - nav) / nav) * Decimal("100"),
        "nav_time": nav_time,
        "price_time": price_time,
        "time_gap_minutes": Decimal(str(gap_minutes)),
        "comparison_is_stale": gap_minutes > 60,
    }

Use QVeris to find and call ETF NAV capabilities用 QVeris 查找并调用 ETF 净值数据能力

• Open the QVeris provider details for relevant ETF or fund-data capabilities.
• Inspect input and output schemas, NAV type, currency, valuation policy, publication time, revision state, and license before letting an agent call a capability.
• Require an explicit fund and share-class identifier, date range, official versus indicative NAV, and freshness tolerance in every tool request.
• Preserve the provider, raw value, identifier, valuation and publication dates, revision, and validation result with every downstream use.

• 打开 QVeris 服务商详情，查看相关 ETF 或基金数据能力。
• 让 AI 智能体调用前先检查输入输出结构、净值类型、币种、估值规则、发布时间、修订状态和许可。
• 每次工具请求都应明确基金与份额标识、日期范围、官方或参考净值，以及时效容忍度。
• 在每次下游使用中保留服务商、原始数值、标识、估值与发布日期、修订号和验证结果。

Free ETF NAV API FAQ免费 ETF 净值 API 常见问题

Authoritative references and related guides权威参考与相关指南