You have a bucket of widgets, and so does everyone else to varying degrees. Each widget is really worth a dollar, but you paid $12 on average for yours because

You have a bucket of widgets, and so does everyone else to varying degrees. Each widget is really worth a dollar, but you paid $12 on average for yours because widgets were in demand at the time. Nobody really needs all their widgets right now, so there is little to no demand. You can either keep holding your widgets and keep them at a $12 valuation on your books, or sell them for an $11 write down. If enough people sell their widgets at $1 then everyone's widgets are magically worth $1 too, and everyone is fucked. Bay Area commercial real estate right now is like holding a bunch of jumbo mortgages in 2007.