Reminiscences of a Stock Operator is interesting, but I would not read it as a manual. The book has sharp observations about markets, patience, crowd psychology, and the strange emotional weather of speculation. That does not mean the techniques transfer cleanly into today.
In fact, copying the posture too eagerly can probably ruin you. The trader in the book is constantly trying to read the tape, size up conviction, survive reversals, and come back after damage. There is skill there, but also a dangerous romance around being broken and rebuilding yourself through the same machine that broke you.
The shadow over the whole thing is Jesse Livermore himself. The book predates his suicide, so that ending is not part of the original story. But knowing it afterwards changes the taste of the myth. Make yourself, break yourself, make yourself again. At some point the question is not whether the market can be beaten, but what kind of life is left around the attempt.
That is what stayed with me most. The pursuit of riches can look heroic from a distance and catastrophic up close. If everything around the trading becomes damaged - family, peace, stability, identity - then even the wins start to look suspicious.
So I keep the book in the library as a classic, but also as a cautionary object. There is intelligence in it, and there is danger in it. The investing and trading are not separate from the person doing them. That might be the most important lesson, even if it is not the glamorous one.