thinkorswim is a trading platform developed by Charles Schwab (TD Ameritrade heritage). The brokers listed here provide access to thinkorswim, the professional desktop trading platform built by TD Ameritrade and now offered by Charles Schwab at no additional cost. thinkorswim provides a fully programmable multi-monitor workstation with thinkScript for custom studies, scans, and alert conditions, alongside options analysis tools covering theoretical pricing, live Greeks, and risk graph visualisation across multi-leg positions. Strategy backtesting against historical data and paper trading with live market prices are both available without subscription approval. When selecting a broker for thinkorswim, verify whether you need a Schwab brokerage account specifically and which asset classes are accessible through the platform in your jurisdiction.