Reading an alternatives ETF: the vocabulary

What correlation, beta, a down week, down-week capture and return against T-bills mean on an alternatives ETF, and why each is measured weekly over one year.

An alternatives fund is sold on behaving differently from stocks, so the words on this desk describe how a fund moved with the S&P 500 rather than what it returned. Each is measured on weekly returns over the last year, because a fund holding futures or foreign shares prices at a different time from the New York close, and a week lets both sides see the same news.

Correlation

How closely the fund’s weekly returns moved with the S&P 500’s over the last year, from −1 to 1. At 1 the two rise and fall together, at 0 there is no pattern, and below 0 the fund tended to move the other way.

Beta

How far the fund moved, on average, for each 1% move in the S&P 500 over the same weeks. At 0.3 it moved about 0.3% the same way; below 0 it moved the other way.

Down week

A week in which the S&P 500 fell, measured through SPY with dividends reinvested. A week that ended exactly level is not a down week.

Down-week capture

The fund’s average return in the S&P 500’s down weeks as a share of the index’s own average in those weeks. At 100% it fell as much, at 50% half as much, and below zero it rose. It is weekly and covers one year, so it is not the same figure as Morningstar’s downside capture.

Against T-bills

The fund’s total return minus a short Treasury bill fund’s (BIL) over the same year, in percentage points. A fund can steady a portfolio and still earn less than cash.

Where to next

Definitions as ETFIQ uses them for alternatives ETFs. Every figure on the site is calculated from published data. Standards and sources

Cite this page. ETFIQ, Reading an alternatives ETF: the vocabulary, data as of Sep 21, 2026. https://etfiq.com/learn/alternatives Free to use with attribution; the underlying files are at Open data.