| ABE ATS | ABEX | 303 ALTERNATIVES LLC | |
| AMERICAN LEDGER ATS | CSTN | AMERICAN LEDGER ATS | Ceased on July 31, 2021 |
| APOGEE | APOG | CITADEL SECURITIES LLC | Ceased on April 2, 2015 |
| AQUA | AQUA | AQUA SECURITIES L.P. | Ceased on September 16, 2022 |
| AX TRADING, LLC | AXTN | AX TRADING, LLC | Ceased on April 30, 2021 |
| BARCLAYS DIRECTEX | BCDX | BARCLAYS CAPITAL INC. | Ceased on October 31, 2018 |
| BIDS ATS | BIDS | BIDS TRADING L.P. | |
| BNPP CORTEX ATS | BNPX | BNP PARIBAS SECURITIES CORP. | |
| BOATS | BLUE | BLUE OCEAN ATS, LLC | |
| CARTAX | CARX | CARTA CAPITAL MARKETS, LLC | Ceased on June 30, 2024 |
| CBX | ICBX | INSTINET, LLC | |
| CIOI | CIOI | CITIGROUP GLOBAL MARKETS INC. | Ceased on September 30, 2018 |
| CITI CROSS | CXCX | CITIGROUP GLOBAL MARKETS INC. | Ceased on April 30, 2019 |
| CITIBLOC | CBLC | CITIGROUP GLOBAL MARKETS INC. | Ceased on March 22, 2022 |
| CITI-ONE ATS | ONEC | CITIGROUP GLOBAL MARKETS INC. | |
| CLEARLIST LLC | CLER | CLEARLIST LLC | |
| CODA | CODA | CODA MARKETS, INC. | f/k/a PDQ ATS |
| CROSSFINDER | CROS | CREDIT SUISSE SECURITIES (USA) LLC | Ceased on August 1, 2023 |
| CROSSSTREAM | XSTM | NATIONAL FINANCIAL SERVICES LLC | |
| DBOT ATS, LLC | DBOX | DBOT ATS, LLC | Ceased on March 31, 2020 |
| DEALERWEB | DLTA | DEALERWEB INC. | |
| EQX LLC | EQXI | EQX LLC | |
| FANTEX BROKERAGE SERVICES, LLC | FTEX | FANTEX BROKERAGE SERVICES, LLC | Ceased on September 2, 2016 |
| FNC AG STOCK, LLC | FNCA | FNC AG STOCK, LLC | |
| GCX | MLCX | BOFA SECURITIES, INC | Ceased on May 20, 2022 |
| GCX | MLCX | MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED | Ceased on May 10, 2019 |
| GLOBAL OTC | ARCA | ARCHIPELAGO TRADING SERVICES, INC. | |
| IBKR ATS | IATS | INTERACTIVE BROKERS LLC | |
| IBKR EOS ATS | IEOS | INTERACTIVE BROKERS LLC | |
| IEX | IEXG | IEX SERVICES LLC | Ceased on September 2, 2016 |
| INSTINCT X | MLIX | MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED | Ceased on May 10, 2019 |
| INSTINCT X | MLIX | BOFA SECURITIES, INC. | |
| INSTINET BLOCKCROSS | BLKX | INSTINET, LLC | Used PULX prior to February 2, 2015. Ownership change: State Street to Instinet eff. August 11, 2017 |
| INTELLIGENTCROSS ATS | INCR | INTELLIGENT CROSS LLC | |
| INVESTX GEM | INVX | INVESTX MARKETS LLC | |
| INX SECURITIES, LLC | SWCL | OPENFINANCE SECURITIES, LLC; INX SECURITIES, LLC | "f/k/a OPENFINANCESECURITIES, OPENFINANCE, OPENFINANCE NETWORK, CFX MARKETS, SAGEWORKS CAPITAL """ |
| JET-X | JEFX | JEFFERIES EXECUTION SERVICES, INC. | Ceased on April 1, 2016 |
| JPB-X | JPBX | J.P. MORGAN SECURITIES LLC | |
| JPM-X | JPMX | J.P. MORGAN SECURITIES LLC | |
| LEVEL ATS | EBXL | EBX LLC | Ceased on February 28, 2022 |
| LEVEL ATS | EBXL | Kezar Trading, LLC | Name change from LEVEL ATS to Kezar Trading LLC |
| LEX MARKETS LLC | LEXA | LEX | Ceased on February 28, 2023 |
| LIGHT POOL | LTPL | CREDIT SUISSE SECURITIES (USA) LLC | Ceased on December 1, 2016 |
| LIQUIDNET H2O ATS | LQNA | LIQUIDNET, INC. | |
| LIQUIDNET NEGOTIATION ATS | LQNT | LIQUIDNET, INC. | |
| LIQUIFI | LQFI | CITIGROUP GLOBAL MARKETS INC. | Ceased on November 7, 2016 |
| LODAS SECURITIES ALTERNATIVE TRADING SYSTEM | ALTS | LODAS SECURITIES, LLC | "ATS name change from Realto Securities Alternative Trading System to LODAS SECURITIES ALTERNATIVE TRADING SYSTEM. Firm name change from Realto Securities, LLC to Lodas Securities LLC " |
| LUMINEX ATS | LMNX | Kezar Trading, LLC | Name change from LUMINEX TRADING & ANALYTICS LLC to Kezar Trading LLC |
| MAGMA ATS | MAGM | TOR BROKERAGE LLC | Ceased on September 4, 2019 |
| MERRILL LYNCH (ATS-1) | MLVX | MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED | Ceased on June 1, 2016 |
| MILLENNIUM | NYFX | CONVERGEX EXECUTION SOLUTIONS LLC | Ceased on June 23, 2017 |
| MS POOL (ATS-4) | MSPL | MORGAN STANLEY & CO. LLC | |
| MS RPOOL (ATS-6) | MSRP | MORGAN STANLEY & CO. LLC | |
| MS TRAJECTORY CROSS (ATS-1) | MSTX | MORGAN STANLEY & CO. LLC | |
| NFSTX, LLC | NFST | NFSTX, LLC | |
| NORTH CAPITAL PRIVATE SECURITIES CORPORATION | PPEX | NORTH CAPITAL PRIVATE SECURITIES CORPORATION | Ceased on June 30, 2019 |
| NORTH CAPITAL PRIVATE SECURITIES CORPORATION | PPEX | "PUBLIC PRIVATE EXECUTION NETWORK, PPEX, PPEX ATS" | |
| NXP | DASH | DASH FINANCIAL LLC | Used DFIN prior to March 21, 2017. Ceased on March 31, 2020 |
| OASIS PRO MARKETS LLC | OPML | OASIS PRO MARKETS LLC | |
| ONECHRONOS | CGXS | ONECHRONOS MARKETS LLC | |
| OTC LINK ATS | OTCL | OTC LINK LLC | MPID change from OTCR to OTCL |
| OTC LINK ECN ATS | OTCX | OTC LINK LLC | |
| OTC LINK NQB IDQS | OTCN | OTC LINK LLC | |
| POSIT | ITGP | VIRTU ITG LLC | Ceased on June 1, 2020 |
| POSIT | ITGP | VIRTU AMERICAS LLC | |
| PROMETHEUM EMBER ATS INC. | PEAT | PROMETHEUM ATS; PEATS | |
| PURESTREAM | PURE | PURESTREAM, LLC | |
| RIVERCROSS | RCSL | RIVER CROSS SECURITES, LP | Ceased on February 1, 2017 |
| SECURITIZE MARKETS ATS | " SMKT" | SECURITIZE MARKETS, LLC | "Name change from Distributed Technology Markets ATS to SECURITIZE MARKETS ATS" |
| SHARENETT ATS | SHNT | SHARENETT SECURITIES LLC | |
| SIGMA X | SGMA | GOLDMAN SACHS EXECUTION & CLEARING, L.P. | Ceased on July 3, 2017 |
| SIGMA X2 | SGMT | GOLDMAN, SACHS & CO. | |
| STARTENGINE SECONDARY | STAR | STARTENGINE PRIMARY LLC | Ceased on December 31, 2019 |
| STARTENGINE SECONDARY | STEN | STARTENGINE PRIMARY LLC | |
| STIFEL X | STFX | STIFEL, NICOLAUS & COMPANY, INCORPORATED | |
| SUPERX ATS | DBAX | DEUTSCHE BANK SECURITIES INC. | Ceased on September 24, 2021 |
| TEXTURE ATS | TXTR | TEXTURE CAPITAL INC. | |
| THE BARCLAYS ATS | LATS | BARCLAYS CAPITAL INC. | |
| THE RIALTO MARKETBOARD | RIAL | RIALTO MARKETS LLC | " f/k/a RIALTO TRADING NETWORK LLC (Had initially Ceased Operations on January 31, 2020" |
| TOR ATS | TORM | Tor Brokerage, LLC | MPID change from TORB to TORM |
| TRADEBOOK | BTBK | BLOOMBERG TRADEBOOK LLC | Ceased on September 1, 2016 |
| TRIPLESHOT | TSBX | TRIPLESHOT, LLC | Ceased on March 1, 2016 |
| tZERO Securities LLC | PROS | tZERO Securities LLC | Name changed from tZERO ATS, LLC to tZERO Securities LLC. f/k/a PRO Securities (PRO Securities LLC). Ceased being an ATS-N filer on 6/18/21 |
| UBS ATS | UBSA | UBS SECURITIES LLC | |
| USTOCKTRADE SECURITIES, INC. | USTK | USTOCKTRADE SECURITIES, INC. | Ceased on January 17, 2022 |
| VARIABLE INVESTMENT ADVISORS, INC. ATS (VIAATS) | VIAT | VARIABLE INVESTMENT ADVISORS, INC. | |
| VIRTU MATCHIT ATS | KCGM | VIRTU AMERICAS LLC | f/k/a KCG MatchIt |
| VIRTU NIGHT MARKET ALTERNATIVE TRADING SYSTEM | VNMS | VIRTU NIGHT MARKET SYSTEM; VIRTU NIGHT MARKET; VNMS | Ceased on February 28, 2019 |
| VORTEX | VRTX | CONVERGEX EXECUTION SOLUTIONS LLC | Ceased on October 1, 2015 |
| XE | WDNX | WEEDEN & CO.L.P. | Ceased on August 5, 2019 |
| XE | PJCX | PIPER SANDLER & CO. | Name change from PIPER JAFFRAY & CO to PIPER SANDLER & CO. Ceased Operations on January 4, 2024 |
