Attached files

file filename
EX-31.1 - EX-31.1 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-31_1.htm
EX-23.1 - EX-23.1 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-23_1.htm
EX-31.2 - EX-31.2 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-31_2.htm
EX-10.28 - EX-10.28 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-10_28.htm
EXCEL - IDEA: XBRL DOCUMENT - INVESTMENT TECHNOLOGY GROUP, INC.Financial_Report.xls
10-K - 10-K - INVESTMENT TECHNOLOGY GROUP, INC.a2223404z10-k.htm
EX-32.1 - EX-32.1 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-32_1.htm
EX-10.14 - EX-10.14 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-10_14.htm
EX-10.11 - EX-10.11 - INVESTMENT TECHNOLOGY GROUP, INC.a2223404zex-10_11.htm

QuickLinks -- Click here to rapidly navigate through this document


Exhibit 21.1


SUBSIDIARIES OF THE COMPANY

Name
  Jurisdiction of
Incorporation/Organization

ITG Inc. 

  Delaware

AlterNet Securities, Inc. 

  Delaware

ITG Software Solutions, Inc. 

  Delaware

ITG Global Trading Incorporated

  Delaware

ITG Solutions Network, Inc. 

  Delaware

ITG Analytics, Inc. 

  Delaware

ITG Investment Research, Inc. 

  Delaware

ITG Platforms Inc. 

  Delaware

ITG Derivatives LLC

  Illinois

Investment Technology Group International Limited

  Ireland

ITG Ventures Limited

  Ireland

Investment Technology Group Limited

  Ireland

Investment Technology Group Europe Limited

  Ireland

ITG Australia Limited

  Australia

ITG Singapore Pte. Limited

  Singapore

ITG Canada Corp. 

  Nova Scotia

TriAct Canada Marketplace LP

  Ontario

ITG Hong Kong Limited

  Hong Kong

Note: Certain subsidiaries were omitted from this list in accordance with Regulation S-K Item 601(b)(21)(ii).




QuickLinks

SUBSIDIARIES OF THE COMPANY