Sector and group RS

After this lesson you'll rank groups before stocks, and you'll know what group confirmation adds to any single chart.

Stocks move in herds

A stock's daily move isn't purely its own. Decompose it and three layers appear: what the whole market did, what the stock's industry group did, and what the stock itself added. O'Neil's studies of decades of winners attributed a large share of a typical stock's move to the first two layers, the market and the group. So looking at a stock without looking at its group leaves out most of what actually moved it, a bit like judging a swimmer without knowing anything about the current.

The mechanism lives one layer up from School I's roster. When the institutions develop a thesis, it's rarely about a single company. The thesis is "AI infrastructure," or "defense budgets," and a thesis that size gets expressed across every credible name in the group at once. That's why group members' charts rhyme, since the same buyers are working right down the list.

So RS gets computed at the group level too, and it works the same way: the group's combined performance against the index, ranked against all other groups. Money rotates, out of last year's favored groups and into new ones, and the group RS ranking is where that rotation shows up. New market advances tend to announce their leadership at group level early, which makes the ranking one of the first places to look when the next course's regime reading says conditions have turned.

Group confirmation

The ranking's second use is as a witness for individual charts. Suppose a stock breaks out of a sound base (School III) on good volume. Now look sideways at its group:

Confirmed: three or four peers are breaking out of their own bases the same week, and the group sits high in the RS ranking. The institutional thesis is being expressed across the whole list, so your stock's move has company, and company counts as evidence.

Alone: the stock's peers are drifting sideways-to-down and the group ranks in the bottom half. The breakout may still work, but it's claiming something unusual, that this one company merits buying while its whole neighborhood gets ignored. Some great stocks do exactly that. They're rarer, and a rare claim earns both skepticism and a modest size.

The checklist School V assembles will make this a standing question, regime first, then group, then stock, with each layer able to veto the next. For now, build the reflex: every time a chart interests you, pull up the group and its strongest member before doing anything else.

Check yourself

1. Why do charts within an industry group look alike? (The institutions express theses at group scale — the same enormous buyers are working every credible name on the list.)
2. A breakout fires in a stock whose group ranks 4th of 100 and whose peers are breaking out too. Versus the same chart in a bottom-decile group, alone. What differs? (The first has the institutional current behind it, and peers breaking out the same week as witnesses. The second is a rare-claim trade and should be sized like one.)
3. Where does new leadership tend to announce itself first after a market turn? (At the group level — the rotation shows in the group RS ranking before most individual charts are repaired.)

The idea this lesson installs

Check the group before trusting the stock.

Next: Course 5 — "Market regime: when the answer is nobody."