CME Security IDs Can Change and Be Reused

Summary

The document explains that CME security identifiers are unique for a given day but are not guaranteed to remain unique or unchanged across time. It answers two data-management questions: whether an identifier can later refer to a different instrument, and whether an instrument keeps the same identifier throughout its life.

The answer says both can happen. A user-defined strategy recreated later may represent the same instrument under a different ID, while an expired instrument’s ID may be reused. CME also does not promise that IDs for ordinary instruments such as futures will remain fixed, although the answer characterizes changes in practice as unlikely. The discussion cites a response attributed to someone who spoke with CME, but supplies no formal specification, examples, or systematic evidence. Researchers matching historical instrument records should therefore avoid treating the ID alone as a permanent identifier and should verify identity against other contract attributes and date context.

Key ideas

• CME security IDs identify one product on a given day, but may not be globally unique over time.
• A recreated user-defined strategy can receive a different ID despite matching an earlier strategy.
• An expired instrument’s ID may later be assigned to another security.
• CME does not guarantee that regular instruments retain the same ID throughout their lifetime.
• Historical data joins should account for identifier changes and possible reuse.

Tags

# Are CME security id's unique and constant over time?


# Are CME security id's unique and constant over time?












For any given day, CME security IDs are unique - a number will always refer to a single product.

Are they unique over time as well? That is, might a new security have a security id that used to be used by an expired one?

And are they constant? That is, does a given security keep the same security id over its lifetime?

## Answer by Cookie (score 3)

https://quant.stackexchange.com/a/16767

Speaking to CME, apparently they are neither unique nor constant.

The obvious case when a security would change id is if it is a user defined strategy, which got created a second time - identical security, but different id.

But CME does not even commit to not changing security ids of regular instruments, such as futures, although in practice they are unlikely to change (this was my understanding of the answer).

Once a security expires, its id might be reused as well.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.