Charles Schwab Corp, the largest discount stockbroker in the US, will market is to market Lotus Development Corp’s Signal and QuoTrek real-time stock market price quotation products, to current and prospective Schwab customers: the $595 Lotus Signal is an MS-DOS-based system designed for the independent investor who trades frequently and includes an FM receiver and software that brings in stock prices in real time; the $450 QuoTrek is a portable quotation monitor that stores and tracks real-time prices in a compact, hand-held device and both also involve monthly subscription fees and exchange charges.