Several thinkorswim components use a single-letter coding for exchange names. Refer to the tables below for explication.
| Options | Stocks | ||
| Letter | Exchange | Letter | Exchange |
| A | NYSE Amex | A | NYSE AMEX |
| B | BOX | B | BOX |
| C | CBOE | C | CINN |
| E | EDGX | D | ECN BEST |
| H | ISE Gemini | F | MF/MM |
| I | ISE | I | ISEG |
| J | ISE Mercury | J | EDGA |
| K | EDGX | K | EDGX |
| M | MIAX | M | CHXE |
| N | NYSE Arca | N | NYSE Arca |
| P | PSE | Q | NASDAQ |
| Q | NASDAQ | S | NASDAQ SC |
| T | NASDAQ OMX BX Options | T | NASDAQ INT |
| W | C2 | U | OTCBB |
| X | PHLX | Z | BATS |
| Z | BATS | V | OTC OTHER |
| W | CBOE | ||
| X | PHLX | ||
| Y | BATS Y-Exchange | ||
| Z | BATS | ||