How to check short interest — and why “who” is not in it

1. Where to find it

FINRA publishes the short interest data (the Short Interest section on finra.org), showing reported shares short and the settlement date per security.

Exchanges post it for their own listings too — Nasdaq for Nasdaq-listed, NYSE for NYSE-listed.

⚠️ Even the latest figure is two to three weeks old. It is compiled on alternate settlement dates and published afterwards, so today’s short interest exists nowhere.

2. One number is not enough — two ratios, two denominators

Shares short on its own means different things at different company sizes, so it is usually read as one of two ratios. The denominators differ, and so do the questions.

Days to cover = shares short ÷ average daily volume. It asks how many days of current trading it would take to buy that back. A larger number means it would take longer.

Percent of shares outstanding = shares short ÷ total shares. It asks how much of the company is sold short.

The two do not move together. A heavily traded stock can be high on the second and low on the first.

3. ★What this data cannot answer — “who”

Short interest is a per-security total. Which institution is short, and by how much, is not disclosed anywhere.

This is easy to confuse with 13F. A 13F reports holdings per institution, but only long positions, and there is no equivalent per-institution reporting for shorts in the US.

When a fund is named in the press as short a stock, it either said so itself or the figure comes from a jurisdiction that does require per-institution disclosure (parts of Europe). US short interest data will not tell you.

⚠️ Nor does it say why. A short can be a bet on decline or a hedge against another position. The number does not distinguish them.

4. Some stocks cannot be expressed as a ratio

ADRs of foreign companies: shares short cover only the US-listed portion while shares outstanding are counted worldwide, so the denominators do not match and the ratio comes out tiny.

ETFs: creation and redemption make the meaning different from ordinary shares. A high ratio on an index ETF does not carry the same reading.

In those cases not calculating is more accurate than showing a calculated figure.

What to keep in mind

• It is always historical. Alternate-period compilation plus publication delay means even the newest figure is two to three weeks behind.
• Nothing about the lending side is included. Borrow fees and available supply are not part of this filing.
• High or low short interest does not indicate direction. The filed number and its date say that much and no more.