One takeaway from the book is that trend following strategies are really difficult to follow. Jesse Livermore had a 3 yearlong losing streak from 2011 - 2014 despite him following his rules. After the events of the book, he went short in 1929 and was reportedly worth over 100m in that time, a huge amount. Then he lost it all in the strongly mean reverting markets of the 1930s where his trend following strategy didn't work.

He was a problem gambler, but I think if we looked at top poker players of today, they'd all have some love the gamble in them. Jesse had godly tape reading skills that allowed him to beat the bucket shops at the start of his career.

After being kicked out of the bucket shops, he should have just become a floor trader and in all likelihood, he'd have had lower highs but would have fared a lot better overall. A lot of the trading cliches like cutting trading losses quickly, letting profits run, averaging up rather than down originate from this book. There is a reason people still talk about it 100 years after its publication. It's a good contender for the best trading book of all time.