Narrow breadth is a funding story this time, not a conviction story

Every few years the market produces a statistic so tidy that it becomes a substitute for thinking. This year's version is that eleven companies account for 71 per cent of the S&P 500 return. The statistic is true. The conclusion usually drawn from it, that investors have crowded into a handful of names out of misplaced enthusiasm and will eventually be punished for it, does not follow from the evidence and has been wrong for three consecutive years.

Narrow breadth has two causes that look identical in the data and behave nothing alike. The first is conviction, where money chases a theme and the rest of the market is ignored. The second is funding, where the rest of the market becomes more expensive to own because its cost of capital has risen. This year is overwhelmingly the second, and the week just past made the mechanism visible.

The gap, and how unusual it is

Through Friday the capitalisation weighted index has returned 15.1 per cent including dividends. The equal weighted version of the same 500 companies has returned 0.9 per cent. A 14.2 point gap at this stage of a calendar year has happened once before in the modern record, in 1999, and the comparison is doing a lot of work in the bearish case being made on trading floors this month.

Look at where the lines separate. They track each other through February, diverge modestly in the spring, and then split decisively from July onward. July is the month the Bellweather Macro term premium estimate crossed from negative to positive. That is not a coincidence, and it is not a story about enthusiasm for eleven companies.

Two different balance sheets

The companies at the top of the index share a financial characteristic that has nothing to do with what they sell. They hold net cash, they fund capital expenditure from operating cash flow, and their weighted average cost of capital barely moves when the credit market reprices. The 450 companies below them are the opposite. They carry net debt, a meaningful share of it floating rate, and they refinance on a schedule set by the market rather than by choice.

When the ten-year yield rises because growth is accelerating, the second group outperforms, because their earnings are more cyclical and their multiples start lower. When the ten-year rises because term premium is repricing, the second group underperforms, because the discount rate goes up while the cash flows do not. Those are opposite outcomes from the same headline move in yields, which is why a strategy note that says higher rates are bad for equities is almost always incomplete.

The indicator worth following

The advance decline line is the traditional breadth measure and it is nearly useless for this purpose, because it counts companies without weighting them by how much their financing costs have moved. The Russell 2000 against the S&P 500 is the better ratio. Small caps carry the floating rate exposure, they refinance more often, and they are the constituency on which a term premium shock lands first. That ratio has fallen 9.4 per cent since the start of July, and about two thirds of the decline arrived after the thirty-year yield crossed 5 per cent in late August.

This framing carries a corollary that most of the bearish commentary skips. If narrow breadth is a funding condition rather than a positioning excess, it does not resolve through a rotation out of the top of the index. It resolves when the funding condition eases, which means when the long end stabilises. Waiting for the eleven to break so that the 450 can catch up has been a losing trade for three years, and the reason it keeps losing is that it misreads what is causing the gap in the first place.

We are not underweight the index leaders because we love them. We are underweight everything that has to refinance in the next eighteen months, and that happens to be the rest of the index.

Theodora Vance, portfolio manager at Kestrel Asset Management

The thirty-year auction on Thursday is therefore an equity event, not merely a rates event. A strong result caps the long end, eases the discount rate on the 450 and would do more for breadth than any earnings season. A weak one extends a pattern that has now run for fourteen months and that most equity portfolios are still mispricing as a story about crowding.