蟹貨 is indeed a common term used in the Hong Kong security market;

FYI:-
蟹 = crab, and
貨 = product, goods; in here it means “stock shares”

The 蟹 here means a special kind of crab, called “大閘蟹” (or hairy crab); this type of crabs is a seasonal product from China, usually available in Autumn.

The exporters would normally tight down each crab with straw or string so that it couldn’t move an inch during the air shipment.

This term is used to describe investors who purchase a certain stock at high price, and facing a low current market value, so that they have no other choices but hold on to those stocks (to avoid selling it at a lost, and hope the stock price will recovery some day); And such HOPE is generally consider “Wishful Thinking”.

災區 = disaster area

So, 蟹貨 could be called “fallen shares”

Then perhaps 蟹貨災區 = “fallen shares disaster area”, “fallen shares trap”.