New Highs and New Lows

New highs and new lows identify securities reaching their highest or lowest eligible prices over a defined lookback period, commonly 52 weeks. For one security, the label describes a price extreme. Across an exchange, index, or watchlist, the counts form a market-breadth measure showing how widely strength or weakness is distributed.

The lookback and universe are essential. “40 new highs” is incomplete unless the reader knows which securities were eligible, which market supplied the data, and whether the test used intraday or closing prices.

Key Takeaways

• A new high or low must use a stated lookback period, often but not always 52 weeks.
• Security-level labels and market-wide counts are two related but different uses.
• New-high and new-low counts measure participation, not the size of each price move.
• A rising index with few new highs can indicate narrow leadership, but it does not guarantee a reversal.
• Counts can differ across providers because of universe, session, price-adjustment, and eligibility rules.
• New highs are not automatic buy signals, and new lows are not automatic bargains.

Two Meanings of the Term

Nasdaq’s glossary defines “new high/new low” at the security level as a stock at its highest or lowest price in the last year. Analysts then aggregate those qualifying securities to study breadth.

Common Breadth Calculations

Two simple calculations summarize the daily counts:

Net new highs = number of new highs - number of new lows

High-low percentage = new highs / (new highs + new lows) × 100

The first produces a positive or negative count. The second shows the share of extreme readings that are new highs. A provider may apply a moving average or use a proprietary variant, so the methodology should be checked before comparing indicators.

If both counts are zero, the percentage formula has no denominator and should be reported as unavailable rather than forced to zero.

How To Interpret the Counts

Breadth is confirming when participation moves in the same general direction as the market benchmark. A divergence occurs when the benchmark and breadth measure move differently. Divergence is an observation, not a timed forecast.

New Highs/New Lows vs. Related Breadth Measures

A security can advance without making a new high, and it can decline without making a new low. That is why new-high/new-low breadth and advance-decline breadth can tell different stories on the same day.

Relationship to 52-Week High and Low

The Stock Quote Price Fields article defines the trailing-year maximum and minimum for one instrument. A new-high or new-low count asks how many instruments in a defined universe reached those thresholds.

That article’s high and low sections define the underlying price fields across sessions and timeframes. The breadth measure adds aggregation; it does not replace those definitions.

Data and Methodology Checks

Before comparing new-high and new-low figures, verify:

1. Universe: exchange listings, index constituents, sector members, or a custom screen.
2. Lookback: 20 sessions, 52 weeks, calendar year, or full history.
3. Price test: intraday high or low, closing price, settlement price, or vendor-defined field.
4. Session: regular trading only or extended-hours activity.
5. Corporate actions: split and distribution adjustments, symbol changes, mergers, and spinoffs.
6. Eligibility: treatment of preferred shares, ETFs, funds, warrants, recent IPOs, halted securities, and thin listings.
7. Constituent history: current membership or point-in-time membership for historical tests.
8. Data timing: live, delayed, end-of-day, preliminary, or corrected counts.

Point-in-time membership matters in backtests. Applying today’s index constituents to past periods can introduce survivorship and look-ahead bias.

Common Mistakes

• Equating a new high with strong fundamentals: the label describes price, not earnings quality or valuation.
• Calling every new low a bargain: a lower price can reflect worsening cash flows, dilution, distress, or changing expectations.
• Ignoring the denominator: 50 new highs can be broad in a small universe and narrow in a very large one.
• Mixing universes: NYSE, Nasdaq, S&P 500, and custom watchlist counts are not interchangeable.
• Mixing daily highs with closes: the qualification method can materially change the count.
• Treating divergence as a deadline: breadth can diverge from an index for an extended period.
• Using one session as a strategy: one breadth reading does not establish expected return or suitable position size.

How Investors and Analysts Use the Measure

New-high and new-low data can help:

• describe whether an index move is broad or concentrated;
• compare participation across sectors or market-cap groups;
• monitor whether strength is expanding or contracting over time;
• provide context for momentum, trend, and risk reviews; and
• challenge a market narrative that relies only on a capitalization-weighted index.

The measure should be paired with index construction, volume, volatility, valuation, macroeconomic conditions, and the user’s actual analytical question. It is descriptive evidence rather than individualized investment advice.

Sources and Further Reading

• Nasdaq Glossary: New High/New Low
• Nasdaq Dorsey Wright Glossary: High-Low Index
• Investor.gov: Stock Quotes
• NYSE: Market Data Products

FAQs

Related Terms

• Stock Quote Price Fields: Session high-low fields, trailing-year boundaries, and price-position context for one instrument.
• Market Sentiment: Aggregate attitudes inferred from market behavior and surveys.
• Trading Volume: Completed activity used to add participation context.

Educational Use

This page is for financial education only. It does not provide personalized investment, trading, tax, legal, or regulatory advice and does not recommend buying or selling a security because it reached a new high or low.