Just been diving into Bob Farrell's investment playbook again, and honestly, this guy's perspective is timeless. For those unfamiliar, Farrell spent nearly 50 years at Merrill Lynch as a technical analyst and market psychologist – basically, he's seen every market cycle imaginable.

What's interesting about Bob Farrell is that he came up studying under Benjamin Graham and David Dodd at Columbia (yeah, the value investing legends), but he carved his own path by focusing on sentiment and market psychology instead of pure fundamentals. By the time he retired, what was once considered unconventional analysis became mainstream. Even George Soros was reading his daily newsletter.

So here are the 10 rules that shaped Farrell's approach:

The first few are foundational: Markets revert to the mean, excesses swing hard in the opposite direction, and history keeps repeating itself – there are no new eras. The dot-com bubble, tulip mania, 2008 housing crash – same pattern, different era.

One that hits different is rule 4 – exponential moves go further than you expect but don't correct sideways. GameStop's insane 2020-2021 rally is the perfect example. Started at $1, hit $5.50, then exploded 1600% to $120 before settling back down. Most people thought it was over at $5.50, but the momentum had other plans.

Then there's the psychological stuff. Rule 5 is brutal: the public buys at the top and sells at the bottom. Fear and greed override long-term plans every single time. Farrell understood that investor discipline is rare – emotions always win when real money is on the line.

Bob Farrell also emphasized that market breadth matters more than individual stock performance. When only a handful of mega-caps are driving the market (like Apple carrying everything), that's actually a warning sign. Healthy markets are broad.

His take on bear markets is useful too – they typically have three phases: the sharp crash, a reflexive bounce where people buy the dip wrong, then the drawn-out grind lower. And here's the contrarian angle: when everyone agrees on something, expect the opposite. David Tepper proved this buying Bank of America in 2009 when sentiment was terrible – turned into a $4 billion win.

Last point from Farrell? Bull markets are just more fun than bear markets. Can't argue with that.

The real lesson from studying Bob Farrell's rules is that market cycles are predictable patterns driven by human behavior. History, crowd psychology, emotions – that's where the edge is. No amount of reading beats actual decades of experience watching these patterns repeat.