The NR7ID is an NR7 that is also an Inside Day — a true "double-compression" setup. This rare technical alignment occurs when a day's trading range is both the narrowest of the past week and completely contained within the high and low of the previous day. By identifying this extreme contraction in volatility, traders can position themselves for the explosive price expansion that typically follows such a significant market squeeze.

An NR7 occurs when the current day's high-low range is narrower than the ranges of each of the previous six days. This identifies the narrowest range in a seven-day period, signaling extreme contraction and low volatility.

An Inside Day forms when today's high is below yesterday's high and today's low is above yesterday's low — the entire range sits inside the prior day's range.

When a day qualifies as both NR7 and Inside Day, it creates a powerful double-compression pattern. Crabel's studies (and follower extensions) suggest this "oddity" builds exceptional pent-up energy, often leading to sharp, directional range expansion on subsequent days.

This aligns with Crabel's foundational thesis: markets cycle between contraction (rest/low volatility) and expansion (movement/trend). The tighter the squeeze, the bigger the potential breakout.

Toby Crabel is a legendary figure in short-term trading, best known for his 1990 book Day Trading With Short Term Price Patterns and Opening Range Breakout. Often called the "manifesto" of volatility-based trading, this dense, data-heavy volume introduced concepts like Opening Range Breakout (ORB), Narrow Range patterns (NR4 and NR7), Inside Days, and the core principle of contraction followed by expansion.

Crabel's research, based on pre-1990 futures data, showed that periods of unusually low volatility (contraction) frequently precede explosive moves (expansion). Among his patterns, dedicated followers hunt for the rare NR7ID — a hybrid that combines maximum compression for potentially violent breakouts.

Crabel's pre-1990 backtests on futures markets (S&P, bonds, currencies, commodities) showed:

Modern adaptations confirm the edge: these setups frequently precede "trend days" with larger ranges and stronger directional moves. The rarity makes NR7ID a high-conviction signal for traders scanning stocks, futures, forex, or indices.

Frequency: NR7 appears dozens of times yearly per instrument; NR7ID is much rarer, improving selectivity.

Day Trading With Short Term Price Patterns and Opening Range Breakout (Traders Press, 1990) is ~288-300 pages of raw backtested tables — no fluff, few charts, mostly stats on patterns like ORB after NR7/Inside Days, multi-bar narrow ranges, and combos.

It went out of print quickly, becoming a collector's item. Physical copies once fetched $500–$1,500+ on secondary markets due to its perceived "code" for short-term edges. Even today (as of early 2026), used hardcovers list for $600–$1,000+ on platforms like Amazon, eBay, and AbeBooks, with pristine or signed copies higher.

PDFs circulate in trading communities, but the original remains prized. Crabel founded Crabel Capital Management, a systematic firm still influenced by these ideas.

The NR7ID embodies Crabel's contraction-expansion philosophy perfectly — extreme low-volatility setups often unleash the strongest moves. While markets evolve, the pattern's logic holds across assets.

For serious short-term or breakout traders, studying Crabel's dense tables (or modern scanners on TradingView) remains foundational. Hunt the NR7ID, pair it with ORB, and respect the volatility cycle — that's the legacy of this 1990 classic.

Related Reading: NR7 trading strategy