That they'll hold it up as long as it suits them. Times are different since JL wrote his books, but the people's psychology is the same. Back then traders only had to worry about some guy cornering the cotton market. Today we have to worry about naked short selling, non-existent shares, and government subsidized market place.
The challenges are different but I'm still trying to figure out how to beat them.
Another book written by JL is called simply "How to trade in Stocks". It pretty much says the same things as "Reminiscences" says, but it's organized as more of a trader-to-trader format.
Market Data 
Markets 
AI
