API Update: Introducing new instrument types for equity swap/index listing
What is changing?
From 15 December 2025, two new instrument types will be added to the BitMEX InstrumentTypes(available via the /instrument REST API endpoint and WebSocket API).
FFSCSX for the Equity perpetual swaps
MRSXXX for indexes used by the Equity perpetual swaps product
Please refer to a snippet example of equity-swap instrument in REST API or WebSocket API below:
"symbol":"CRCLUSDT",
"rootSymbol":"CRCL",
"state":"Open",
"typ":"FFSCSX",
Why are we making this change?
The addition of the new instrument types is a necessary preparatory step for the upcoming listing of equity swap products.
This is an additive change, meaning it introduces new instrument types without removing any existing data. Most integrations should be unaffected.
If you have any questions about these upcoming changes, please contact Support.
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