Market Alerts

TDTMS:  Attached please find the minutes from our meeting last week, 3/23.  If there are any additions or corrections, please reach out to leadership.

TDTMS Meeting
March 23rd, 2026, 1:30 PM
WebEx

Monica Jones opened the meeting, read the anti-trust admonition, and introduced attendees.
Minutes from the 2/23/26 meeting were reviewed with one minor correction:  add Tomas Fernandez to the attendee list.
ACTION items were reviewed:  Sheri noted the housekeeping items from the main meeting page were submitted, yet not completed by ERCOT.  WG will check again next meeting for completion.

ERCOT Updates

 IT Report & SLAs

• Vikrum presented the March IT report noting the NAESB upgrade went well, yet commenting about the March NAESB certificate upgrade where one market participant reported issues. All SLAs were met.
• MT performance is operating as expected and in line with other months. Tomas questioned how the availability is calculated since he has experienced MT latency issues within the last few weeks with the system also unavailable.  Per ERCOT, if MT experiences issues with a duration of less than 30 minutes it is not counted in the metric.
  • Tomas asked if ERCOT was proactive vs reactive to monitor exception logs/errors/alerts and take action
  • Mick Hanna stated ERCOT would review recent performance timing and availability
• 3/18 MarkeTrak was experiencing issues and ERCOT indicated the vendor reported high usage of memory during this time. ERCOT is waiting for a recommendation
  • ACTION: Mick Hanna/Vikrum will research the # of licenses used during the 3/18 issues to determine if this contributed to the issue
• 3/18 Vistra reported MT issues with IAG subtype where state was not updating. For example, a MT was remaining in a state of ‘regaining BGN submitted’ when the BDMVI had already been submitted.  Per Tammy Stewart, a configuration issue was corrected where the MTs were not transitioning to ‘auto-complete’

ERCOT IT Projects – in general, not a lot of significant updates

• MT API – development should be complete by mid-April, then will move to testing with a Q3 launch to production. No external impacts are expected other than possible new end point/URL change.
  • Tomas asked if reports would be available through the API. Mike Dameron responded it was possible, yet it would require a project with market participant support.  The upload and download of reports through the API will be added to the TDTMS Agile Enhancements list
  • ERCOT also reported they were reviewing the overall API strategy and will discuss during the next Technology Working Group meeting
  • ERCOT stated a small WSDL change will occur for designating a report destination when updating background reports.  Dave Michelson had stated in an earlier meeting this feature has not been used in years
• Public Website Cipher Security Hardening – TLS 1.2 to TLS 1.3 upgrade noting some market participants are already utilizing TLS 1.3 with ERCOT supporting
• MIS Updates – Retail API & UI current application is aging and will be upgraded. ERCOT currently planning and reviewing changes within the next 3-4 months and go live will not occur until Q3/Q4 of 2027.  TDTMS pointed out the two items on the Enhancements list for inclusion with the upgrade.
• MarkeTrak & Siebel upgrade – last year only a Siebel upgrade was completed; no major upgrade scheduled for this year
• Digital Certificates – a presentation was to be made at TWB on 3/26 and ERCOT will likely present at the next RMS as well; PRS approved NPRR1302 and 1306 and will be coming back to PRS for a ‘no-impact’ IA. Nick Reedy is scheduled to present at 4/14 RMS since RMGRR 184 will also require approval for the removal of a ‘digital certificate’ and allow flexibility for authentication

 ERCOT Market Performance Measures – Retail

Dave Michelson had provided an earlier report which was shared by Sheri:  once the changes are in place to Subst. Rule 25.88, the market performance measures report will no be provided unless there were performance issues.  ACTION:  what is the new threshold in order to generate a report?

Quarterly Review of ERCOT IGL Report

A few notables from the brief discussion and review of the November 2025 IGL report:

• Contributors to the volume of IAGs in the market has shifted over time to those REPs where > 1% of their enrollments result in IAGs. The volume of the > 1% and the < 1% used to closer in value.  For November, 3435 IAGs were from the > 1% group, while only 513 were from the < 1% group.
• Majority of top offenders have most of their volumes not identified by themselves (i.e. Inadvertent Losses were submitted) For example, REP #7 had 7% of enrollments result in IALs being submitted to them for the month of November and for the last 12 months, their IAL volumes were > 3%.
• It is understood, a REP may have a bad month, however, to have consistently higher numbers, they are an outlier
• Time to process a MT has significantly decreased since TXSET 5.0
• Questions were raised if REPs that do not attend TDTMS or RMS are aware of their performance. Sheri noted last year or the year prior, TDTMS partnered with Client Services in communicating to all REPs what their anonymous number was as well as sending the report.
• The ask is to leverage Client Services to communicate the message to REPs again and perhaps on an annual basis ACTION:  Tomas and Sheri will draft a message for REPs noting the Losing REP is the participant who performs all the work yet is not the one who made the mistake.

TDTMS Main Meeting Page – Administrative Clean Up
Sheri submitted the changes to Stakeholder Services.  The WG will follow up next meeting to see if completed.

MarkeTrak Deep Dive
Small group discussions will be scheduled before the next in person TDTMS meeting and the results will be reviewed at the in-person meeting held in May

 TDTMS Meeting Dates – balance of year
All meetings are scheduled for Mondays at 1:30 PM.  Leadership for TXSET/LP and TDTMS met to review proposed schedule:

No April date * revised after TXSET/LP discussion
May 4^th – in person @ ERCOT Met Center * reflects revised after TXSET/LP discussion
June 15^th
            No July date
August 3^rd
            September 21^st
            October 19^th
            November 16^th
            No December date

Only Q2 dates will be posted to the ERCOT calendar.

DRAFT AGENDA for May 4th meeting – 1:30 PM, Monday

• ERCOT Updates
  • IT Report
  • MT performance issues
    • 3/18 issue – root cause and licensing
  • Retail Market Performance Measures report – what is the new threshold?
  • Projects
    • MT API
    • 2 to 1.3
    • MIS updates – Retail API & UI
    • Digital Certificates – NPRRs/RMGRR status
    • Other projects
  • Enhancements list – updates – MT API reporting upload/download
  • ERCOT IAS Report & Client Services
  • TDTMS Main Meeting Page – housekeeping check
  • MT Deep Dive – review results of 2025(2)

After TXSET/LP meeting last week, the proposed meeting schedule for Q2 had changed.  We will not have a scheduled meeting in April and our meeting for May will be moved up to May 4^th, Monday, from 1:30 – 5 PM.  Note, the May 4^th meeting will be an in-person meeting held at the ERCOT Met Center also offering WebEx as well.  Between now and May 4^th, the smaller group will be working on the MarkeTrak analysis from 2025(2) and provide results at the in-person meeting.

Below is a draft agenda of the May 4^th meeting.

DRAFT AGENDA for May 4th meeting – 1:30 PM, Monday

• ERCOT Updates
  • IT Report
  • MT performance issues
    • 3/18 issue – root cause and licensing
  • Retail Market Performance Measures report – what is the new threshold?
  • Projects
    • MT API
    • 2 to 1.3
    • MIS updates – Retail API & UI
    • Digital Certificates – NPRRs/RMGRR status
    • Other projects
  • Enhancements list – updates – MT API reporting upload/download
  • ERCOT IAS Report  & Client Services
  • TDTMS Main Meeting Page – housekeeping check
  • MT Deep Dive – review results of 2025(2)

monica.jones@centerpointenergy.com

robert.bevill@tmnp.com

sheri.wiegand@txu.com

Sheri Wiegand | Vistra
Market Relations | 1925 W John Carpenter Fwy, Irving, TX 75063 | 972-979-5225 (m) | sheri.wiegand@txu.com

Source:
Texas Data Transport and MarkeTrak Systems Working Group TDTMS@LISTS.ERCOT.COM on behalf of; Wiegand, Sheri <Sheri.Wiegand@TXU.COM>; (Texas Data Transport and MarkeTrak Systems Working Group via LISTS.ERCOT.COM)
To:  TDTMS@LISTS.ERCOT.COM