10 Years of the ISDA SIMM

As the derivatives industry prepared for the September 2016 implementation of initial margin requirements for non-cleared derivatives, one challenge stood out: counterparties needed to agree on the amount of initial margin to be exchanged. But if each firm developed its own model to calculate initial margin amounts, the result would be chaos, with disputes, delays and increased risk. A common model was needed that everyone could use - one that was credible, transparent and easily replicable. The answer was the ISDA Standard Initial Margin Model (ISDA SIMM), a pioneering industry solution that continues to shape how the derivatives market tackles major industry challenges today.

As we approach the 10-year anniversary of the first phase of initial margin requirements this month, it's easy to forget how significant this was. Firms had the choice of using a standard schedule set by regulators, but many believed it would produce overly conservative outcomes for most portfolios. The only viable option was to put competitive rivalries aside and work together through ISDA to develop a single, transparent and risk-sensitive model that everyone could trust and use. Without that common framework, agreeing margin amounts quickly and efficiently would have been almost impossible.

From the outset, we realized that transparency was essential. To gain the confidence of both market participants and regulators, the ISDA SIMM's methodology, assumptions and calibration framework were made publicly available. Anyone can see how the model works and how margin requirements are determined. We also set up a governance forum and executive committee, which coordinate ongoing monitoring, development and maintenance of the model. Recalibration is a critical part of that process, and the ISDA SIMM moved to a semiannual calibration cycle in 2025, allowing it to respond more quickly to evolving market conditions - making the ISDA SIMM truly unique as an industry margin model for non-cleared derivatives in terms of governance and frequency of recalibration. So far, we've made 17 updates to the ISDA SIMM to ensure it remains risk appropriate, reflecting changing market conditions, new products and evolving risk dynamics. On top of that, ISDA shares detailed calibration, backtesting and performance-monitoring information with global regulators and maintains regular dialogue on the model's evolution.

Without that level of industry coordination under the ISDA umbrella, and without that level of transparency, it's difficult to see how the margin rules could have been implemented as smoothly as they were. A decade later, the ISDA SIMM is permitted for use by regulators in more than 40 countries, is used by more than 400 groups of entities and is supported by nearly 70 vendors. It has also proven resilient through some of the most volatile market conditions in recent memory. What began as a regulatory necessity has become a cornerstone of the non-cleared derivatives market, supporting safer and more efficient risk management around the world.

Just as importantly, the success of the ISDA SIMM demonstrated that the industry could come together to solve complex market structure challenges through a common, transparent standard. That blueprint has since been applied to a range of other initiatives. The transition away from LIBOR is one example, but it also informed the development of mutualized industry solutions like the ISDA Digital Regulatory Reporting initiative built on the Common Domain Model, the ISDA Notice Hub and ISDA Create. Ten years after its rollout, the ISDA SIMM remains far more than a model for calculating initial margin. It established a framework for industry collaboration that continues to support the modernization of derivatives markets today.