---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-21-344336"
form_type: "8-K"
ticker: "MKTX"
cik: "0001278021"
company_name: "MARKETAXESS HOLDINGS INC"
filed_at: "2021-12-01T23:59:59+00:00"
generated_at: "2026-06-28T04:22:33.787451+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# MarketAxess CIO Nick Themelis to retire; new CIO hired, starts March 1, 2022

## Summary
- Nick Themelis notified his retirement from MarketAxess on November 24, 2021.
- New CIO has been hired, currently on garden leave, and will join on March 1, 2022.
- Themelis will remain as CIO until the successor starts, then serve as advisor through February 2023.
- Company plans to announce the new CIO's name in the first quarter of 2022.

## SEC filing metadata
- accession: 0001193125-21-344336
- form_type: 8-K
- ticker: MKTX
- cik: 0001278021
- company_name: MARKETAXESS HOLDINGS INC
- filed_at: 2021-12-01T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/0001193125-21-344336-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/d244325d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-21-344336
- JSON: https://secwatch.observer/filing/0001193125-21-344336.json
- Plain text: https://secwatch.observer/filing/0001193125-21-344336.txt

## Key facts
- Executive change
  Nick Themelis departed as Chief Information Officer at MARKETAXESS HOLDINGS INC.
  - Action: intends to retire
  - Role: Chief Information Officer
  source text: On November 24, 2021, Nick Themelis notified MarketAxess Holdings Inc. (the “Company”) that he intends to retire from the Company.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/0001193125-21-344336-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.