Aggregates (Per Minute)
WS
Delayed: wss://delayed.polygon.io/indices
Real-Time: wss://socket.polygon.io/indices
Stream minute-by-minute aggregated OHLC (Open, High, Low, Close) for a specified index via WebSocket. These aggregates update continuously in Eastern Time (ET) and capture changes in the index’s values. Unlike stocks or options, index aggregates are derived from index values rather than individual trades. If no new index updates occur within a given minute, no bar is emitted. By providing an ongoing feed of updated market snapshots, this endpoint enables users to track intraday index movements, refine analysis, and power real-time market visualizations.
Use Cases: Real-time monitoring, dynamic charting, intraday trend analysis, market research.
Parameters
ticker
string
required
Specify an index ticker using "I:" prefix or use * to subscribe to all index tickers.
You can also use a comma separated list to subscribe to multiple index tickers.
You can retrieve available index tickers from our Index Tickers API.
Response Attributes
ev
enum (AM)
The event type.
sym
string
The symbol representing the given index.
op
number
Today's official opening value.
o
number
The opening index value for this aggregate window.
c
number
The closing index value for this aggregate window.
h
number
The highest index value for this aggregate window.
l
number
The lowest index value for this aggregate window.
s
integer
The start timestamp of this aggregate window in Unix Milliseconds.
e
integer
The end timestamp of this aggregate window in Unix Milliseconds.