What is the AAII Investor Sentiment Survey?

The AAII Investor Sentiment Survey polls individual (retail) investors weekly on whether they are bullish, neutral, or bearish over the next six months. The headline number is the bull–bear spread — bullish % minus bearish % — read contrarian at the extremes.

How to read it — a contrarian gauge

Because AAII measures how ordinary investors feel, it is usually read contrarian at the extremes: retail sentiment tends to peak near market tops (everyone already bought) and bottom near lows (everyone already sold). Example (illustrative): 45% bullish and 25% bearish is a bull–bear spread of +20 — a fairly optimistic reading a contrarian treats with mild caution. A deeply negative spread is the mirror image and has historically leaned mildly bullish.

Why "mild" is the key word

AAII is a weak contrarian indicator, not a precise one. Sentiment can stay stretched for months without the market turning, and it tells you how the retail crowd feels rather than what institutions are doing. Quantustik tracks it as one sentiment input to its broader market-conditions read — a supporting colour, never a standalone signal.

Frequently asked questions

What is the AAII bull-bear spread?

The bullish percentage minus the bearish percentage from the weekly survey. A large positive spread means retail is broadly optimistic; a large negative spread means broadly pessimistic.

Why is AAII read contrarian?

Retail sentiment tends to peak near market tops and bottom near lows, so extreme optimism leans mildly bearish and extreme pessimism leans mildly bullish.

How reliable is it?

Only mildly. It is a self-selected weekly survey of a few hundred individuals and sentiment can stay stretched for months. Quantustik uses it as one input to a broader Market Conditions score.

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Related terms

Educational research only — not investment advice.