Green wood is freshly cut wood that has not dried out yet. When wood is seasoned, internal moisture has evaporated making it more suitable for industrial use. Green lumber is a type of lumber that still has a high internal moisture level.
In some tree species, it is better to work with the lumber while it is still green. Green lumber is also and actively traded commodity, which you can find where commodity options, futures and forwards are traded.
When knowing and doing is not the same
So, the story goes that there was this trader who enjoyed a very successful long term career in trading a commodity called Green Lumber. However, it was only after having had traded the commodity for years when someone told him told him that green lumber wasn’t actually green in color. This story was retold by Nassim Taleb in his book Antifragility.
The moral of the story is that even though the trader had honed his skills in trading the commodity over his carrier (the doing), he did not have to know every single detail about green lumber, how it is produced, what the value chain looks like, the macro-economic factors affecting the price of the commodity.
A related analogy from Nassim Taleb is that you don’t lecture birds on how to fly. Birds learn to fly by doing, by trial and error. They do not go to flight school and listed to theories on aerodynamics.