Alternative display facility

Alternative display facility (ADF) is an equity trading facility created in the United States by NASD, a self-regulatory organization (SRO). The ADF is an alternative to the exchange for publishing quotations and for comparing and reporting trades. This differs from a trading facility with execution capabilities (stock exchange) in that the exchange would simply send back to the owner of the displayed order a notice of execution. The National Association of Securities Dealers NASD has operated an ADF since July 29, 2002.
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