Free Open Interest API
for Options Research用于期权研究的
免费未平仓量 API
Learn what free open interest data really includes, which limits matter, and how to turn raw option-chain fields into useful signals.
了解免费未平仓量数据究竟包含哪些内容、哪些限制最关键，
以及如何将期权链原始字段转化为有用的研究信号。
TL;DR核心摘要
Open interest is the number of outstanding option contracts, usually reported by contract, strike, expiry, and call or put side.
Free access often comes with delayed updates, narrow market coverage, short history, or strict daily request limits.
It is useful for screening liquidity, mapping positioning, and tracking changes—not for proving whether traders are bullish or bearish by itself.
Verify timestamps, update frequency, historical depth, contract identifiers, licensing, and whether zero values mean zero or missing.
未平仓量是尚未了结的期权合约数量，数据通常按具体合约、行权价、到期日以及看涨期权或看跌期权类别提供。
免费访问通常会受到数据更新延迟、市场覆盖范围有限、历史数据区间较短或每日请求次数限制严格等约束。
这类数据适合筛选流动性、描绘持仓分布和跟踪变化，但仅凭未平仓量本身，无法判断交易者整体看涨还是看跌。
应核查数据时间戳、更新频率、历史数据深度、合约标识符和许可条款，并确认数值为零究竟代表未平仓量确实为零，还是数据缺失。
Fields a useful open interest API should return实用的未平仓量 API 应返回哪些字段
A usable response needs enough identity and timing data to distinguish contracts and compare observations safely. Open interest without an as-of date, expiry, strike, and option type is difficult to trust.
实用的 API 响应必须包含充分的合约标识与时间信息，才能准确区分不同合约，并可靠地比较各观测时点的数据。若未注明数据截至日期、到期日、行权价或期权类型，就难以判断未平仓量数据是否可信。
Underlying symbol, standardized contract symbol, expiration date, strike price, and call/put type prevent accidental joins between different contracts.
An explicit as-of date and market timezone tell you whether the value is current, delayed, or the previous session’s official figure.
Volume, bid, ask, last price, implied volatility, and underlying price help separate active contracts from stale or illiquid listings.
Store daily snapshots yourself when the API does not return open-interest change. Compare like-for-like contract identifiers across sessions.
标的资产代码、标准化合约代码、到期日、行权价以及看涨或看跌类型，可避免在关联数据时误将不同合约匹配在一起。
明确的数据截至日期和市场时区，有助于判断该数值是当前值、延迟值，还是上一交易时段的官方统计值。
成交量、买价、卖价、最近成交价、隐含波动率和标的资产价格，有助于区分交易活跃的合约与报价陈旧或流动性不足的合约。
若 API 不直接返回未平仓量变化，应自行保存每日快照，并按相同的合约标识口径比较不同交易日的数据。
Treat open interest as a dated clearing snapshot把未平仓量视为带日期的清算快照
A quote can update throughout the session while its open-interest field still describes the previous clearing cycle. Keep separate fields for quote time and open-interest as-of date; never substitute the API retrieval time for either one. A value of zero must also remain distinct from null, unavailable, and not-yet-published.
报价可以在盘中持续变化，但同一条记录里的未平仓量仍可能来自上一轮清算。应分别保存报价时间与未平仓量截至日期，不能用 API 请求时间代替其中任何一个。数值为 0、字段为空、暂不可用和当日尚未发布也必须采用不同状态表示。
Preserve contract identity through adjustments在合约调整前后保留准确身份
Store the full standardized contract symbol plus underlying, expiration, strike, call/put side, multiplier, root, and adjustment status. Splits, mergers, and special distributions can create adjusted contracts whose deliverable is no longer a simple 100-share lot. Joining only on strike and expiration can silently combine different instruments.
除标准化合约代码外，还应保存标的代码、到期日、行权价、认购或认沽方向、合约乘数、root 代码与调整状态。拆股、并购或特别分派可能生成交割物不再等于 100 股普通股票的调整合约；若只按行权价和到期日关联，容易把不同合约悄悄合并。
Free open interest API access options免费未平仓量 API 获取渠道
“Free” should be evaluated endpoint by endpoint, not by provider name. A supplier may offer a free API key while reserving current options chains, full history, or exchange-entitled fields for a paid plan. Check the live plan and documentation before designing around a request allowance.
判断“免费”时，应以具体接口为单位，而不是只看供应商名称。某个服务即使免费发放 API key，也可能把当前期权链、完整历史数据或需要交易所授权的字段放在付费套餐中。正式设计请求频率前，应以供应商当下的套餐页和文档为准。
| Access type获取渠道 | Typical benefit主要优势 | Common free-tier limit免费套餐的常见限制 | Best for适用场景 |
|---|---|---|---|
| Broker API券商 API | Option chains alongside trading accounts and quotes.可在交易账户中同时获取期权链和报价行情。 | Account required; redistribution may be restricted.通常需要开立账户，且可能限制数据再分发。 | Personal tools and execution workflows.个人工具和交易执行流程。 |
| Market-data API市场数据 API | Cleaner symbols, broader endpoints, and easier automation.合约标识更规范、数据接口覆盖更广，也更便于自动化处理。 | Delayed data, low request caps, or limited history.数据可能延迟、请求额度较低，或历史数据跨度有限。 | Research prototypes and scheduled screens.研究原型与定时筛选任务。 |
| Exchange files交易所文件 | Authoritative definitions and official aggregate statistics.权威的合约定义和官方汇总统计。 | Bulk formats; contract-level history may be paid.通常以批量文件提供，合约级历史数据可能收费。 | Validation and market-level analysis.数据校验和市场整体分析。 |
| QVeris | Discover and inspect suitable financial-data capabilities.发现并评估合适的金融数据服务能力。 | Provider entitlements and limits still apply.仍须遵守数据提供方的授权范围和使用限制。 | Agents that need auditable capability selection.需要对数据能力选择过程进行审计的智能体。 |
Compare suppliers with one controlled request用同一个受控请求比较供应商
Useful when a brokerage-oriented option-chain endpoint fits the application. Confirm account requirements, market-data status, expiration filters, and whether the returned open interest is delayed or prior-session data.
Useful for a market-data workflow that also needs contract reference data, quotes, trades, snapshots, or aggregates. Verify the subscribed options tier and the timestamp attached to each field.
Useful for prototyping historical US options requests with an API key. Its documentation distinguishes historical and realtime functions, so do not infer realtime access from a historical response.
Useful as an exchange source for market statistics, product definitions, and commercial datasets. Public market totals are not a substitute for contract-level historical open interest.
适合需要券商型期权链接口的应用。接入前要确认账户要求、行情权限、到期日筛选方式，以及返回的未平仓量是延迟数据还是上一交易日数据。
适合还需要合约参考数据、报价、成交、快照或聚合行情的市场数据流程。应核对已订阅的期权套餐，并逐项检查字段对应的时间戳。
适合用 API key 验证美国期权历史数据原型。其文档会区分历史与实时接口，不能因为历史接口返回了数据，就推断已经获得实时权限。
适合查阅交易所市场统计、产品定义和商业数据集。公开的市场汇总数字不能替代逐合约历史未平仓量。
Build a reliable open-interest pipeline构建可靠的未平仓量数据管道
1. Define the research clock1. 先确定研究时钟
Decide whether the screen runs after the official daily update, before the next open, or intraday with prior-session open interest. Document that choice beside the signal so later readers do not mistake a slow-moving clearing measure for live positioning.
先确定筛选是在官方日度数据更新后、下一交易日开盘前，还是在盘中结合上一交易日未平仓量运行。这个口径应和信号一起记录，避免后来把变化较慢的清算指标误当成实时持仓。
2. Save immutable daily snapshots2. 保存不可变的每日快照
Partition raw responses by supplier, market date, underlying, and retrieval time. Retain the original payload before normalization. Calculate change in open interest only after matching the same contract identity across two valid as-of dates; a single snapshot cannot reveal whether positions were opened or closed.
原始响应可按供应商、市场日期、标的代码和抓取时间分区，并在标准化前保留完整载荷。只有将同一合约在两个有效截至日期的快照准确匹配后，才能计算未平仓量变化；单份快照无法说明持仓是新增还是减少。
3. Validate before ranking contracts3. 排序合约前先做校验
- Reject duplicate contract-and-date keys and impossible negative values.
- Flag missing expirations, malformed standardized symbols, and unexplained multiplier changes.
- Measure chain coverage against the contract master rather than assuming a short response is complete.
- Keep volume, open interest, quote freshness, and spread as separate screening dimensions.
- 拒绝合约与日期键重复的记录，以及不可能出现的负值。
- 标记到期日缺失、标准合约代码格式错误和无法解释的乘数变化。
- 将返回结果与合约主数据对照评估覆盖率，不能把较短的响应默认当作完整期权链。
- 成交量、未平仓量、报价新鲜度和价差应作为彼此独立的筛选维度。
4. Separate concentration from direction4. 区分持仓集中度与方向判断
Large open interest can identify strikes where many contracts remain outstanding, but it does not disclose which side initiated each trade or whether positions are hedged elsewhere. Put/call ratios and changes in open interest are descriptive inputs; combine them with price, volatility, volume, and an explicit hypothesis rather than labeling them automatically bullish or bearish.
较高的未平仓量可以指出合约集中在哪些行权价，却不会告诉你每笔交易由哪一方主动发起，也无法识别是否在其他市场进行了对冲。认沽认购比和未平仓量变化属于描述性输入，应结合价格、波动率、成交量和明确假设分析，不能自动贴上看涨或看跌标签。
Where QVeris fits in open interest researchQVeris 在未平仓量研究中的作用
The exact QVeris Options Chain Tool is strongly relevant because its public capability record includes calls and puts by expiration and strike together with volume and open interest. Use that record to inspect inputs and response shape, but still verify market coverage, as-of semantics, history, and entitlements with a small test.
QVeris 的 Options Chain 工具与本页高度相关：它的公开能力记录明确包含按到期日和行权价组织的认购、认沽数据，并返回成交量与未平仓量。可以先据此检查输入参数和响应结构，但市场覆盖、截至时间语义、历史深度和授权范围仍应通过小规模测试确认。
- Run one known underlying and expiration in the QVeris Playground before automating a full chain.
- Confirm that open interest, volume, strike, expiration, and option side are present and correctly typed.
- Record the tool ID, parameters, raw response, retrieval time, and validation result with the analysis.
- 批量自动化之前，先在 QVeris Playground 中测试一个已知标的和到期日。
- 确认未平仓量、成交量、行权价、到期日和期权方向均存在且类型正确。
- 把工具 ID、请求参数、原始响应、抓取时间和校验结论与分析结果一起保存。
FAQ常见问题
Usually not. Many markets publish official open interest after clearing, so an API can have live quotes while open interest reflects the prior session.
No. Volume counts contracts traded during a period; open interest counts contracts that remain outstanding.
No. You need matched observations from at least two clearing dates, and even the change does not identify trader direction or intent.
Correct contract identity, an explicit as-of date, stable coverage, enough request capacity, and terms that permit the intended storage and display.
通常不是。许多市场会在清算完成后发布官方未平仓量数据。因此，即使 API 提供实时报价，其中的未平仓量也可能反映上一交易时段的情况。
不同。成交量统计一段时间内成交的合约张数，未平仓量统计尚未平仓的合约张数。
不能。至少需要匹配两个清算日期的同一合约记录；即使得到变化量，也无法直接判断交易者的方向和意图。
它应提供准确的合约身份、明确的截至日期、稳定覆盖和足够请求额度，许可条款也必须允许预期的数据保存与展示方式。
References and next steps参考资料与下一步
Tradier option chains
Polygon options API
Alpha Vantage options documentation
Cboe options statistics