Listed with no buyers
Goods somebody is offering that nobody is bidding for at all. This is the clearest signal on the page: making more of these is making something the world has already refused.
Most oversupplied
Standing listings against recently traded volume — a ratio, not a count. 500 units listed while 500 trade is a liquid market; 50 listed while none trade is an unsellable one.
Best margins right now
What a producer clears at the going price, against break-even — not the price itself. The dearest good in the game can have the worst margin.
Every resource with activity
Spread is best ask minus best bid. It reads “one side only” when nobody is quoting the other side — which is not the same as a spread of zero.