USAM used to be an SEC registrant, but voluntarily deregistered in 2001, becoming a Pink. It's clearly an abandoned shell, and completely dark. I'm surprised nobody's hijacked it.
Since it has no registered stock, the SEC can't finish it off by revoking registration. There's no mechanism that would allow the SEC just to get rid of it. It could suspend it, thereby sending it to the Greys, as part of one of its Shell-Expel sweeps. But it hasn't done any of those in more than a year.
Since June, it's even been trading most days, for no apparent reason. Before that, it was only trading a few times a year; in my view FINRA could and should have deleted the ticker then as an "inactive issue". That's the only way to get rid of abandoned public shells of this kind.