Two stocks with the same chart pattern can behave differently for a reason neither chart shows. One sits in a sector outperforming the index; the other sits in a sector lagging it. Sector rotation is the name for that difference, and it is measurable rather than intuitive.
What sector rotation means
Sector rotation is the movement of capital from one industry sector to another. Sectors do not move as one block. The index return is an average across them, so at any moment some sectors sit above that average and some below.
For a swing trader the use is narrow and practical. Rotation does not tell you what to buy. It tells you where to look first, and which side of the market you are working against.
The business cycle model
One widely published framework ties sector leadership to the phase of the economic cycle. Fidelity sets out a version of it in "The Business Cycle Approach to Equity Sector Investing". Its figures come from US equity market returns from 1962 through 2020, using GICS sectors.
Here is what the paper says, in its own words.
Early cycle. "Generally, a sharp recovery from recession, marked by an inflection from negative to positive growth in economic activity". Fidelity reports that "sectors that have performed well in the early cycle are interest rate-sensitive (CND, FIN, RE) and economically sensitive (IND, IT, MATS) sectors". It names consumer discretionary, financials and real estate as the sectors that "historically have outperformed the broader market".
Mid cycle. "Typically the longest phase of the business cycle", averaging nearly four years. Average annual stock market performance in this phase "has tended to be fairly strong (14%)". This is the phase where the model helps least: Fidelity records that "sector leadership has rotated frequently in the mid-cycle phase, resulting in the smallest sector performance differentiation of any business cycle phase".
Late cycle. Fidelity describes "an overheating stage for the economy when capacity becomes constrained". Average duration is about a year and a half, with market performance averaging 5% annualised. "As the economic recovery matures and inflationary pressures build, the energy sector has typically performed well", alongside defensive sectors including consumer staples and utilities. Information technology and consumer discretionary "have lagged most often".
Recession. "Features a contraction in economic activity. Corporate profits decline and credit is scarce for all economic actors." Historically the shortest phase, under a year on average. "Defensive-oriented sectors (CNS, UTL, and HTH) have tended to outperform", meaning consumer staples, utilities and health care.
Two limits sit on all of that, and Fidelity states both. Every exhibit carries the standard past-performance disclaimer. Its sector rotation page warns that "by adopting a sector rotation strategy, you run the risk that your portfolio may experience increased volatility and may underperform the broader market indexes".
Add two more of your own. The data is US. And a cycle phase is labelled with confidence only after it has passed.
So treat the cycle as background, not a signal. What you can measure today is relative strength.
Measuring rotation with relative strength
Divide a sector's index by the broad market index and plot the ratio. A rising ratio means the sector is outperforming the benchmark over that window. A falling ratio means it is underperforming. That is all the ratio says: it is a statement about relative performance, not evidence about where money moved.
Add the ratio's own momentum and you get four states, which is what a rotation map plots. Swingfolio's Trade Ideas page has a Sectors tab, headed Sector Performance, that labels them this way. The comparison runs against the ASX 200 for Australian sectors and the S&P 500 for US ones.
- Leading: outperforming the benchmark and still gaining ground
- Improving: underperforming the benchmark but gaining ground
- Weakening: outperforming the benchmark but losing momentum
- Lagging: underperforming the benchmark and losing ground
The map is a description of the last few weeks, not a forecast of the next few. A sector in the weakening quadrant has not yet underperformed; it has stopped extending its lead.
Using it in a swing trading process
Rank, then filter. Sort the sectors by relative strength and draw candidates from the top of that list rather than from a screen across the whole market. It narrows what you look at. It decides nothing.
Find the strong stock inside the strong sector. A sector reading is an average. Within a leading sector some constituents are dragging it, and those are not the ones the ranking was pointing at.
Recheck on a schedule. Rotation readings change slowly enough to review weekly and fast enough that a month-old ranking is stale.
Do not read the map as a forecast. Buying a lagging sector because it "should" turn is a prediction about the future dressed up as analysis. The map has no view on that.
Where this goes wrong
Chasing a sector after the move. By the time a sector is unmistakably leading, part of the move is behind you, and the ranking cannot tell you how much.
Holding a lagging sector and arguing with the reading rather than acting on it.
Concentrating in one sector. Positions in the same sector are not independent, so the risk is larger than the count of positions suggests.
Ignoring the market direction. A sector can lead the index down.
Measuring your own sector edge
The ranking tells you which sectors are strong. It does not tell you whether you trade them well, and those are different questions.
Swingfolio answers the second from your own record. The Sector P&L card on the Analytics page breaks your closed trades down by sector, as a treemap beside a table of P&L, trades and win rate per sector. That is where you find out whether the sectors you favour are the ones paying you.
The Sectors tab on the Trade Ideas page covers the first question. It ranks AU or US sector baskets on 1-day, 1-week, 1-month and year-to-date returns plus relative strength, and marks each one's rotation quadrant. An Open column counts the positions you already hold in each sector. Readings are end of day, stamped with the date they were computed.
Start the 30-day trial and check your last year of trades against the sectors you have been trading.