Market monitoring

The ISO Department of Market Monitoring (DMM) keeps a close watch on the efficiency and the effectiveness of the California ISO markets and the Western Energy Imbalance Market (WEIM). Our reports and presentations provide transparency to the market participants, regulators, policy makers, and other stakeholders. We provide recommendations for market design and operational changes, and monitor for potential detrimental market behavior.

Reports, presentations, filings and comments

Transparency and potential corrective actions

A transparent and open market is the best way to achieve competitive electricity prices. However, situations may develop where corrective action is needed to ensure that the market continues functioning in a fair and efficient manner. Response actions include the following:

  • Seek tariff and protocol changes to improve market efficiency and fairness
  • Seek changes to market power mitigation rules, bid caps or floors and mitigation procedures
  • Report and refer to regulatory agencies for possible enforcement action

Because operating the California grid is a complex undertaking, the ISO will always be reviewing its rules and protocols with an eye towards improving the efficiency of the market.

Market monitoring hotline

Call (800) 644-6409 or use this online form to ask questions or report suspected abuses in the California ISO markets and the Western Energy Imbalance Market.

All information received will be kept strictly confidential, and used only to investigate complaints of market abuse. Reports may be made anonymously.

Suspected abuses may also be reported to the Federal Energy Regulatory Commission Enforcement Hotline.

For complaints about retail electric customer service, please contact the local utility or California Public Utilities Commission Consumer Affairs at (800) 649-7570.


Do you have feedback or comments for the DMM?

The Department of Market Monitoring and the Oversight Committee are interested in your feedback and suggestions regarding the core functions and service provided by DMM. Responses will remain anonymous and providing contact information is optional. Submit your comments and feedback.

For more information, please contact the DMM at

More about DMM

The Federal Energy Regulatory Commission (FERC) requires every regional transmission operator to have an independent market monitor. DMM serves as the independent market monitor for the California ISO markets and Western Energy Imbalance Market (WEIM). DMM is overseen by the DMM Oversight Committee of the Board of Governors.

Our mission statement

To provide independent oversight and analysis of the California ISO markets for the protection of consumers and market participants by the identification and reporting of market design flaws, potential market rule violations, and market power abuses.

See Appendix P of the ISO Tariff to learn more about the ISO's market monitoring.

Core functions

Monitor market performance

Monitor market performance to identify potential anti-competitive market behavior or market inefficiencies.

Assess market rules and ISO operational practices

Identify ineffective market rules or ISO operational practices and recommend changes to improve wholesale competition and efficient market outcomes.

Conduct market analysis (efficiency)

Provide analysis on market performance with particular focus on the structural competitiveness and efficiency of the wholesale markets and the effectiveness of bid mitigation rules to remedy the potential exercise of market power.

Conduct market analysis (investment signals)

Evaluate the effectiveness of the markets in signaling needed investment in generation, transmission, and demand response infrastructure and identify any potential barriers that impede the market's ability to provide needed investments.

Refer market violations to FERC

Collect information regarding market rule violations and refer to FERC for enforcement.

Manage coordination with regulatory/legal entities

Coordinate and assist with referrals, investigations and inquiries by other regulatory and legal entities.

Provide advice to management and Board

Provide independent advice to the California ISO CEO and Board on market related matters.

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