The ability to direct trading within a brokerage's offering through a retirement plan such as a 401(k). As opposed to being limited to the investment options within a sponsored 401(k), some investors have the option to set up a "window", which allows them to trade most listed stocks, mutual funds and exchange-traded funds. May also be known as a "self-directed account" (SDA) or "self-directed brokerage account" (SDBA). The brokerage window is a relatively new convention, but it is quickly gaining popularity as more companies give the option to their employees. While the freedoms of a brokerage window are too much for some investors to consider, it is a viable option for those who understand the increased risks of individual security selection and asset allocation.