Why put and call spread comparisons require caution

Scans run April 6 – 10, 2026 via Spreadsearch

Editorial note (September 25, 2026): This page was substantially revised to replace the original scan-data summary with a methodology note. The original URL and reporting period have been retained for continuity.

Purpose of the scans

These scans were part of an early test of Spreadsearch across a non-exhaustive group of US equity options. The sample included calls and puts from several sectors, with minimum bid and volume filters applied.

One result appeared particularly important during the review: calls and puts could show very different average percentage spreads. That difference was visible in this sample, but the scans did not establish a general difference between calls and puts across the wider options market.

Why the comparison requires caution

The two groups were not directly comparable. The sample did not contain the same number of calls and puts, or matching contracts with the same strikes, expiries, prices, and trading activity. A difference between the two averages could therefore reflect the composition of the sample.

Percentage spreads depend on the price of the option. The same dollar difference between the bid and ask produces a larger percentage spread on a lower-priced contract. This can make groups containing more low-priced options appear wider even when the dollar spreads are similar.

Liquidity at ticker level is not enough. An actively traded underlying can still have individual option contracts with limited activity. Each strike and expiry needs to be assessed separately.

A wider put spread is not evidence of a bearish view. A displayed spread is a point-in-time quote. Without a controlled sample and additional information, it cannot show why one group of contracts was wider or what market participants expected.

What changed in later reports

This early test showed the limits of comparing broad groups through one average. Later Spreadsearch reports used a more stable panel and stricter filters, while keeping dollar and percentage spreads separate.

This public summary does not reproduce the original contract-level market data. Its purpose is to record the methodological lesson from the test.