# Securing the Oracle

On August 6, UMA passed the [**UMIP-189**](https://discourse.uma.xyz/t/umip-189-approve-new-managedoptimisticoraclev2-deployment/2229) governance proposal. This outcome had been long anticipated by the Polymarket community, with early ideas about it starting to surface following the [Wizard Chronicles](/polymarketguide-archive/case-studies/the-wizard-chronicles.md). In that case, two proposers, Wizard and Lonfus, lost a combined $32,250 in proposal disputes, one of the largest losses in UMA's history.

<figure><img src="/files/xXtCj7NM4LAzPEoDpC4v" alt=""><figcaption></figcaption></figure>

With the passing of **UMIP-189** came the introduction of the **ManagedOptimisticOracleV2 (MOOV2)** contract, which implemented several key changes. The most notable were:&#x20;

* Restricting who can propose via a whitelist maintained by Polymarket and Risk Labs (UMA team)
* Allowing Polymarket to better manage its proposal bond&#x20;
* Allowing Polymarket to more easily update its resolution process settings

<figure><img src="/files/1hS4se6BuwnM8HptZEOf" alt=""><figcaption></figcaption></figure>

**The most controversial change in the MOOV2 contract was the creation of a whitelist for proposers.**&#x20;

The passing of UMIP-189 marked one of the most consequential governance decisions in UMA and Polymarket's history. It redefined the Polymarket oracle and set the stage for this case study. In this case study, we will explore the MOOV2 contract proposer whitelist update, the rationale for the change, how the community responded, and possible compromises.&#x20;

#### Coming Up

With the background of the UMIP-189 proposal established, we begin this case study by examining its major changes.&#x20;


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