S&P 500 regime: Panic · as of November 6, 2026 close

Market regime research

Research on how markets behave under stress

DoubleTrends L.L.C. is a quantitative research firm. We study market regimes, drawdowns and how investors behave in them, put our methods and records out in full, and take on outside quantitative research and data engineering work.

Image: New York Stock Exchange, Broad Street, 1908. Photograph by Irving Underhill. Library of Congress.
What we do

Research, validation, and a public indicator

Research

Notes on S&P 500 drawdowns, investor behavior and the measures behind market regimes — plain language, the data on the page, the limits spelled out.

Research

Validation

AlphaVerify, open-source software that checks whether a trading signal’s edge holds up next to markets with no signal in them. The full mathematical specification is published with it.

Validation

The Regime Indicator

A rules-based daily read of S&P 500 stress going back to December 1995, published along with its methodology and every signal it has given.

DoubleTrends™

Open-source research

AlphaVerify: does a signal beat chance?

An open-source framework that pits a trading signal’s apparent edge against 1,000 synthetic markets with no signal in them. Popular conditions often lose: on the NASDAQ since 2015, the golden cross shows a 24.5-point swing in the odds — yet signal-free markets turn up one at least as strong 8.4% of the time.

Findings and methodSource code

From AlphaVerifyThe golden cross, tested against 1,000 signal-free markets
Golden cross on the NASDAQ: a 24.5-point swing in the odds of a 4 percent move whose score falls below the 95th percentile of 1,000 synthetic markets.

Left: shift in the odds of each move while the condition holds. Right: its score (blue) against the synthetic markets; the dashed line is the 95th percentile it must beat. Not cleared.

Research

Recent research notes

All research
How we work

Standards a reader can check

The firm’s commitments are written down and every one of them can be checked on this site.

Principles

Methods are published
How each rule in the indicator is built is laid out in its methodology.
Records are complete
Every signal since Aug 1998 is listed with what came after it, early ones included. Back-tested history is labelled that way.
How we are paid
Subscriptions are priced near what the daily reading costs us to run, research services are billed per engagement. We accept no payments from brokers or exchanges. Details