| State Street Securities Hong Kong Limited | Private company limited by shares | Live |
| STEPHIL SECURITIES LIMITED | Private company limited by shares | Live |
| STOCKWELL SECURITIES LIMITED | Private company limited by shares | Live |
| STONE SECURITIES MARKETS LIMITED | Private company limited by shares | Live |
| Stuttgart Securities Limited | Private company limited by shares | Dissolved |
| SUCCESS SECURITIES LIMITED | Private company limited by shares | Dissolved |
| Success Securities Limited | Private company limited by shares | Live |
| SULMAN SECURITIES LIMITED | Private company limited by shares | Dissolved |
| Suncorp Securities Limited | Private company limited by shares | Live |
| Sundelity Securities Limited | Private company limited by shares | Live |
| SUNNY SECURITIES INVESTMENT LIMITED | Private company limited by shares | Live |
| SUNRISE SECURITIES LIMITED | Private company limited by shares | Live |
| SUN'S GROUP'S SECURITIES LIMITED -THE- | Private company limited by shares | Dissolved |
| SUNSHINE SECURITIES LIMITED | Private company limited by shares | Live |
| SUPERYIELD SECURITIES LIMITED | Private company limited by shares | Dissolved |
| SUPREME CHINA SECURITIES LIMITED | Private company limited by shares | Live |
| SURPLUS SECURITIES LIMITED | Private company limited by shares | Dissolved |
| SUTHERLAND SECURITIES LIMITED | Private company limited by shares | Dissolved |
| SWORDFISH SECURITIES LIMITED | Private company limited by shares | Dissolved |
| SZEHOPE SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| TAIFAIR SECURITIES LIMITED | Private company limited by shares | Live |
| TAIFOOK SECURITIES COMPANY LIMITED | Private company limited by shares | Live Commenced dormancy on 09-Oct-2015 |
| TAIHE SECURITIES LIMITED | Private company limited by shares | Live |
| Taiping Securities (HK) Co Limited | Private company limited by shares | Live |
| FIRST TAISEC SECURITIES HK LIMITED | Private company limited by shares | Dissolved |
| Citadel Securities Taiwan Limited | Private company limited by shares | Live |
| FIRST TAIWAN SECURITIES (HONG KONG) LIMITED | Private company limited by shares | Dissolved |
| TAKAYAMA SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TAKFONG SECURITIES LIMITED | Private company limited by shares | Live |
| TANGSHANG SECURITIES LIMITED | Private company limited by shares | Live |
| TARZAN SECURITIES INVESTMENT LIMITED | Private company limited by shares | Live |
| TELOSO SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TETRA SECURITIES LIMITED | Private company limited by shares | Dissolved |
| WAH THAI SECURITIES LIMITED | Private company limited by shares | Live |
| KGI SECURITIES (THAILAND) INTERNATIONAL HOLDINGS LIMITED | Private company limited by shares | Live |
| THING ON SECURITIES LIMITED | Private company limited by shares | Live |
| THOMAS SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| THUNDER SKY SECURITIES INVESTMENT CO. LIMITED | Private company limited by shares | Dissolved |
| Thunder Stone Securities (Hong Kong) Limited | Private company limited by shares | Live |
| TIANDA SECURITIES LIMITED | Private company limited by shares | Live |
| TIANON SECURITIES COMPANY LIMITED | Private company limited by shares | Dissolved |
| CHINA TIANXIA SECURITIES LIMITED | Private company limited by shares | Live |
| TIMES SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| TIMPS SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TOKAI TOKYO SECURITIES (ASIA) LIMITED | Private company limited by shares | Live |
| Hua Tong Securities Limited | Private company limited by shares | Live |
| Da Shi Tong Securities Limited | | Live |
| Tonsin Securities Limited | Private company limited by shares | Live |
| TOPMORE SECURITIES LIMITED | Private company limited by shares | Live |
| TORNESS SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TOYO SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TOYO SECURITIES ASIA LIMITED | Private company limited by shares | Live |
| MASTER TRADEMORE SECURITIES LIMITED | Private company limited by shares | Live |
| Citadel Securities Arbitrage Trading Limited | Private company limited by shares | Live |
| Citadel Securities Asia Trading Limited | Private company limited by shares | Live |
| CARNAC SECURITIES TRADING LIMITED | Private company limited by shares | Dissolved |
| BLACK SAND SECURITIES TRADING LIMITED | Private company limited by shares | Live |
| TRANS JOY SECURITIES LIMITED | Private company limited by shares | Live |
| TRANS PACIFIC SECURITIES PROPRIETARY LIMITED | Private company limited by shares | Dissolved |
| TREASURE SECURITIES LIMITED | Private company limited by shares | Live |
| TREASURE SECURITIES LIMITED | Private company limited by shares | Live |
| Treasure Capital Securities Limited | Private company limited by shares | Live |
| TRICAPITAL SECURITIES LIMITED | Private company limited by shares | Dissolved |
| Tricor Securities Limited | Private company limited by shares | Live |
| TRIDENT SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TRILINGS SECURITIES LIMITED | Private company limited by shares | Dissolved |
| TRINITY SECURITIES CO. LIMITED | Private company limited by shares | Live |
| TRIODES SECURITIES LIMITED | Private company limited by shares | Dissolved |
| BANKERS TRUST SECURITIES (PACIFIC) LIMITED | Private company limited by shares | Dissolved |
| TRUSTFUL SECURITIES LIMITED | Private company limited by shares | Live |
| TRUTH SECURITIES LIMITED | Private company limited by shares | Live |
| TSUN CHI YUEN SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| TUNG TAI SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| TUNG SUN SECURITIES CO. LIMITED | Private company limited by shares | Dissolved |
| TUNG YAT SECURITIES LIMITED | Private company limited by shares | Live |
| TUNG CHOW SECURITIES BROKERS, LIMITED | Private company limited by shares | Dissolved |
| HANG TUNG SECURITIES LIMITED | Private company limited by shares | Live |
| TURING SECURITIES LIMITED | Private company limited by shares | Live |
| Tyee Securities Limited | Private company limited by shares | Live |
| U-CYBER INVESTMENT (SECURITIES) LIMITED | Private company limited by shares | Dissolved |
| UNI-ALPHA SECURITIES LIMITED | Private company limited by shares | Dissolved |
| UNICORN SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| UNIFIED SECURITIES LIMITED | Private company limited by shares | Dissolved |
| UNIFIED SECURITIES HOLDINGS LIMITED | Private company limited by shares | Dissolved |
| UNI-QUANTUM SECURITIES ASIA LIMITED | Private company limited by shares | Dissolved |
| UNITED SECURITIES LIMITED | Private company limited by shares | Dissolved |
| HK UNITED SECURITIES COMPANY LIMITED | Private company limited by shares | Dissolved |
| UNITED SECURITIES LIMITED | Private company limited by shares | Dissolved |
| CHINA UNITED SECURITIES LIMITED | Private company limited by shares | Dissolved |
| UNITED CHINESE SECURITIES LIMITED | Private company limited by shares | Dissolved |
| FIRST UNITED SECURITIES CO., LIMITED | Private company limited by shares | Dissolved |
| United Prolific Securities Limited | Private company limited by shares | Live |
| UNIVERSAL SECURITIES LIMITED | Private company limited by shares | Dissolved |
| UNIVERSAL SECURITIES ADVISORS LIMITED | Private company limited by shares | Dissolved |
| Universal Huang Chow Securities Company Limited | Private company limited by shares | Live |
| NEW UNIVERSE SECURITIES (HK) LIMITED | Private company limited by shares | Live |
| UNIVEST SECURITIES LIMITED | Private company limited by shares | Live |
| UPBEST SECURITIES COMPANY LIMITED | Private company limited by shares | Live |
| UPBEST ONLINE SECURITIES LIMITED | Private company limited by shares | Live |
| UPMAX SECURITIES LIMITED | Private company limited by shares | Live |