do stocks usually go up on monday? quick guide

Do stocks usually go up on Monday? This article explains the Monday (weekend) effect, reviews the academic history and empirical evidence, explores candidate causes, and gives practical guidance fo...

2026-01-18 03:25:00

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Monday effect (Do stocks usually go up on Monday?)

Do stocks usually go up on Monday? That question sits at the center of the so-called "Monday effect" or "weekend effect," a calendar anomaly in equity markets that many researchers have studied for decades. In short: do stocks usually go up on monday? Historical research shows there are measurable weekday patterns in some samples, but results are mixed, time-varying, and generally small relative to trading costs. For most buy-and-hold investors, the pattern is not a reliable reason to change portfolio strategy; for nimble traders it can be one input among many if tested carefully and executed on a low-cost venue such as Bitget.

As of 2026-01-22, according to Investopedia and select academic summaries, the Monday effect remains a documented but unstable anomaly: some studies find negative average Monday returns versus Fridays, some find reversals concentrated in specific intraday windows, and others find the pattern disappears after accounting for transaction costs and structural changes in markets.

Definition and terminology

The labels "Monday effect" and "weekend effect" describe related observations about predictable differences in daily stock returns across weekdays. Two common formulations appear in the literature and investor discussions:

Momentum formulation (Friday-to-Monday continuation): Monday returns tend to follow the direction of Friday’s returns, creating short-term momentum from the close on Friday to the open or close on Monday.
Reversal / negative weekend effect: Monday returns tend to be lower on average than Friday returns, producing a negative differential for Monday relative to other weekdays.

Both formulations are often used under the umbrella phrase "do stocks usually go up on monday?" — investigators ask whether Mondays are systematically stronger or weaker than other days and whether patterns are predictable enough to trade.

Key definitions:

Monday effect (weekend effect): A calendar anomaly where average returns on Mondays differ (often lower) from those on other trading days.
Paired Friday–Monday test: A common test that compares returns from Friday’s close to Monday’s close, isolating weekend effects that happen between trading sessions.

History and discovery

The formal academic interest in day-of-week effects began in the early 1970s. Frank Cross’s influential 1973 paper documented systematic differences between Friday and Monday returns in U.S. equity markets. Cross compared returns across weekdays and found that, historically, Mondays delivered lower average returns than other weekdays, a result that spurred further study.

After Cross, many papers revisited the effect across different samples, countries, and time periods. Some high-level findings across follow-up work include:

The original Friday/Monday asymmetry was observable in several markets in mid-20th century samples.
The magnitude and significance of the effect varied across decades and jurisdictions.
Periods of attenuation or disappearance were documented; regulators and market observers (including the Federal Reserve and major exchanges) noted that structural changes such as market hours, electronic trading, and shortened settlement times could weaken calendar anomalies.

As markets evolved — with decimalization of quotes, electronic limit order books, and greater institutional participation — researchers repeatedly tested whether the Monday/weekend effect persisted.

Empirical evidence

Empirical evidence on the Monday effect is broad but mixed. Results depend heavily on the sample period, the market studied (country, index), the instrument (large-cap vs small-cap stocks), and the exact testing methodology.

In summary:

Some long-sample daily-return studies reproduce a negative average Monday return relative to other weekdays (the classic weekend effect).
Other studies show the effect diminishes or disappears when accounting for transaction costs, bid-ask spreads, or when using more recent data.
Intraday analyses reveal the location of abnormal returns is often not uniform across the trading day; results sometimes concentrate in the opening or afternoon sessions on Monday.
Cross-sectional work documents that firm-level characteristics (size, liquidity, short interest, analyst coverage) modulate the effect.

Below we review several strands of empirical work with more detail.

Classic daily-return studies

Early empirical work — including Cross (1973) and follow-up research in the 1970s and 1980s — typically compared average daily returns by weekday using the trading-day close-to-close returns. Key, repeatable observations included:

Fridays often had higher average returns than Mondays in several historical samples.
When researchers isolated returns from Friday’s close to Monday’s close, the average differential was statistically significant in some samples, implying a weekend-related return pattern.
Summary statistics from early studies reported average Monday returns that were several basis points lower than average Friday returns; while small in absolute size, the pattern was robust to some statistical specifications in mid-century samples.

These classic studies framed the central question: do stocks usually go up on monday? The standard answer from this literature was cautious: sometimes, but not always, and the effect size was modest.

Time variation and structural breaks

The Monday effect is highly time-varying. Multiple papers document structural breaks:

The effect weakened or disappeared across some subperiods, for example during late 1980s through the 1990s in certain samples.
Changes in market microstructure — such as the shift from fractional to decimal pricing, growth in algorithmic trading, and extended trading hours — altered the behavior of intraday and overnight returns.
Regulatory events (short-selling rule changes, settlement-cycle reforms) and macro shocks (major crises) can temporarily intensify or mute calendar patterns.

Put simply: patterns observed in one era may not persist in another. That time variation helps explain why different studies report different conclusions about whether "do stocks usually go up on monday?"

Intraday granularity and new findings

More recent research uses intraday tick or minute data to locate where weekday effects appear within the trading day. Important intraday observations include:

Some studies find that Monday abnormal returns are concentrated in the first few minutes after the open, consistent with price discovery reacting to weekend information.
Other work documents afternoon reversals on Monday: a pattern where prices move in one direction early in the day and partially reverse later, implying that the net close-to-close Monday effect masks richer intraday dynamics.
A specific paper titled "Reversal of Monday returns: It is the afternoon that matters" (Finance Research Letters / ScienceDirect) finds evidence that Monday afternoon return behavior explains much of the average weekday pattern in certain samples.

Intraday findings complicate simple trading rules: if the effect concentrates in a narrow window, execution costs and slippage matter more, and opportunities are more operationally demanding.

Cross-sectional differences

The magnitude and sign of weekday anomalies vary across stocks. Cross-sectional insights include:

Size and liquidity: Small-cap and illiquid stocks often show stronger calendar anomalies. Large-cap, highly liquid stocks tend to show weaker or no Monday effect.
Short interest and investor disagreement: Stocks with higher short interest or greater disagreement among investors sometimes display larger weekend-related moves, which can amplify Friday–Monday dynamics.
Sector and news-sensitivity: Sectors that frequently release earnings or news on specific days may exhibit compounded weekday effects.

These cross-sectional differences mean a blanket answer to "do stocks usually go up on monday?" is impossible; the correct response depends on which stocks and which time periods you examine.

Candidate explanations

Researchers have proposed several hypotheses to explain the Monday/weekend effect. Brief descriptions of the main candidates follow:

Short-selling and hedging behavior: Short sellers or hedgers may cover positions before weekends to avoid overnight risk, producing buying pressure on Fridays and possible reversals on Mondays.
Weekend news timing: Firms or news outlets sometimes release negative news after markets close on Friday; the accumulation of weekend information can cause Monday price moves as markets assimilate news.
Investor sentiment and behavioral biases: Weekend mood, regret, or recalibration of expectations may shift investor willingness to buy on Mondays or sell after weekend reflection.
Institutional flows and portfolio rebalancing: Some institutional processes (salary flows, cash inflows, portfolio rebalancing) may follow a weekly schedule that disproportionately affects turn-of-week trading.
Market microstructure changes: Historical low liquidity or specific trading rules around weekends created conditions for larger weekend returns in past decades; modernization of trading can reduce these effects.

All plausible explanations likely interact: market structure sets the stage, information arrival and behavioral responses drive flows, and institutional constraints determine execution patterns.

Implications for trading and investment strategies

How should investors interpret the Monday effect? Practical implications differ by horizon and cost sensitivity.

For day traders and short-term strategies: Traders who operate intraday or overnight may test rules that incorporate day-of-week signals, but they must account for execution risk and transaction costs. Intraday-specific patterns (e.g., Monday morning spikes or Monday-afternoon reversals) can be actionable only when combined with robust execution and risk controls.
For long-term investors: The Monday/weekend effect, when present, is typically small relative to expected long-term returns and portfolio-level volatility. It should not drive major strategy changes such as market timing that increase trading frequency or tax events.
For systematic strategies: Any calendar-based rule must be backtested across multiple regimes, account for transaction costs and slippage, and include out-of-sample validation to reduce the risk of data-snooping.

Bitget note: Traders seeking low-fee, high-efficiency venues for short-term strategies should consider trading on platforms with competitive execution and risk tools. Bitget provides features tailored to active traders and can be part of a structure that tests intraday or day-of-week strategies responsibly.

Transaction costs and statistical significance

Observed average differences in many studies are often small — only a few basis points per day on average. Once bid-ask spreads, commissions, financing costs, and slippage are included, many simple calendar-based trades become unprofitable.

In statistical terms:

A statistically significant mean difference does not guarantee economic significance after costs.
Thinly traded stocks may show large raw effects but also have large implicit costs when entering and exiting positions.

Hence, answers to "do stocks usually go up on monday?" that rely only on raw historical means often overstate the tradability of the phenomenon.

Risk of crowding and changing effects

When a pattern becomes widely known and capital chases it, the anomaly tends to shrink or vanish. This is a classic adaptive-markets dynamic:

Arbitrageurs and algorithmic funds can arbitrage away simple predictable returns.
Increased participation on known calendar edges increases liquidity at those times and reduces excess returns.

Therefore, even a historically robust weekday effect can become ephemeral once exploited at scale.

Applicability to other asset classes (including cryptocurrencies)

The bulk of Monday/weekend effect evidence comes from equity markets, especially U.S. stocks. Applicability to other asset classes varies:

Bonds and FX: Day-of-week patterns in other asset classes exist in some samples but are generally weaker and more dependent on macro schedule and liquidity.
Cryptocurrencies: Crypto markets trade 24/7 and are not subject to a "weekend close" in the same way as stock markets. That changes the mechanism for weekend effects. Empirical findings in crypto are mixed: some analyses report weekend or weekday biases in returns or volumes, but drivers likely differ (24/7 liquidity, retail-heavy flows, on-chain events). Calendar patterns in crypto, if present, should be studied separately from equity weekend effects.

Practical takeaway: Do not assume equity weekday patterns transfer unchanged to crypto or other asset classes. If you are testing cross-asset weekday strategies, control for market hours, liquidity, and different participant mixes. For crypto-specific trading, Bitget and Bitget Wallet offer 24/7 trading and custody features that are operationally well aligned with continuous-market strategies.

Criticisms, limitations and robustness concerns

Several methodological concerns limit strong claims about the Monday effect:

Data snooping: Repeated testing across multiple patterns can produce spurious significance if researchers do not correct for multiple testing.
Sample selection: Results depend on start and end dates, country selection, and which stocks are included (survivorship bias can be an issue).
Market microstructure evolution: Changes in trading hours, participants, and technology mean old results may not apply today.
Non-uniform replication: Many studies fail to replicate the effect consistently across samples or after controlling for other risk factors.

Because of these concerns, rigorous studies use out-of-sample testing, multiple robustness checks, and transaction-cost adjustments before claiming persistent, exploitable anomalies.

How researchers study the effect (methodology)

Researchers and quantitative traders commonly apply the following methods to study weekday effects:

Daily return comparisons: Comparing average returns by weekday using close-to-close returns, with t-tests and non-parametric checks.
Paired Friday–Monday tests: Directly comparing returns from Friday close to Monday close isolates weekend accumulation of returns.
Event studies: Controlling for firm-specific news releases and macro events to isolate calendar timing from news-driven moves.
Intraday decomposition: Using minute- or tick-level data to split the trading day (open, midday, close) and locate where anomalies occur.
Factor-adjusted regressions: Controlling for known risk factors (market, size, value) to see whether weekday effects persist after standard risk exposures.
Cross-sectional tests: Sorting stocks by size, liquidity, short interest, or analyst coverage to explore heterogeneity.

Good empirical practice includes transaction-cost modeling, out-of-sample testing, and robustness to alternative specifications.

Practical guidance and takeaways

Short practical answers and guidance for readers who ask: do stocks usually go up on monday?

Short answer: Historically there have been weekday patterns, including a negative Monday or weekend effect in some samples, but the effect is inconsistent and small. Many modern datasets show attenuation of the pattern.
For long-term investors: Do not change your core asset allocation or long-term approach solely because of weekday patterns. Trading more frequently to capture small calendar edges usually increases costs and tax friction.
For traders and quant strategies: If you plan to exploit day-of-week signals, do thorough backtesting across regimes, account for spreads and slippage, test intraday entry/exit rules, and validate out-of-sample. Use low-cost, high-execution-quality platforms. Bitget provides tools and cost structures that can help explore short-horizon strategies responsibly.
If you are curious: Monitor intraday volume and volatility distributions across weekdays; these often provide more actionable input than raw close-to-close means.

References and external links

Below is a bibliographic-style list of key academic and educational sources cited in this article (titles and outlets; no external URLs provided):

Cross, Frank. "The behavior of stock prices on Fridays and Mondays." (1973) — early documentation of weekday return asymmetries.
Finance Research Letters / ScienceDirect. "Reversal of Monday returns: It is the afternoon that matters." — intraday decomposition of Monday effects.
Investopedia. "What Is the Monday Effect on Stock Market Prices?" — investor-focused summary (reported as of 2026-01-22).
Investopedia. "Weekend Effect" — overview article explaining calendar anomalies.
The Motley Fool. "What Is the Monday Effect?" — investor education piece.
Chase. "Why Day-of-the-Week Investing Is Ineffective" — commentary on practical limitations.
IG. "What is the best time to buy and sell shares?" — practical timing considerations.
Yahoo Finance / GOBankingRates. "Monday selling" related articles summarizing popular explanations.

(Readers can search the listed titles on trusted information platforms to access the full articles.)

Final thoughts and next steps

If your question is simply "do stocks usually go up on monday?" — the research answer is: sometimes, historically, but not reliably for all markets or periods. Patterns are modest, time-varying, and often not economically exploitable after costs. Traders interested in short-term edges should combine day-of-week signals with intraday analysis, robust transaction-cost modeling, and disciplined risk management.

If you want to experiment with day-of-week or intraday strategies, consider the following practical steps:

Backtest thoroughly across multiple decades and subperiods, and across the specific universe of stocks you plan to trade.
Include realistic commissions, spread costs, and slippage models in your simulations.
Validate with out-of-sample and live paper-trade testing before risking capital.
Use a low-cost, execution-focused platform; Bitget offers trading tools and a wallet ecosystem that can support active and institutional workflows.

进一步探索: Learn more about market microstructure, intraday return patterns, and implementation costs. Test any hypothesis on a demo account and prioritize risk control and capital preservation.

Note on sources and current reporting: 截至 2026-01-22，据 Investopedia and Finance Research Letters 报道, the Monday/weekend effect continues to be an area of active research with mixed empirical conclusions. Readers looking for the original empirical dates and sample windows should consult Frank Cross (1973) and subsequent Finance Research Letters intraday studies for precise datasets and measured effect sizes.

Interested in testing short-term ideas with controlled fees and advanced order types? Explore Bitget's trading features and Bitget Wallet for secure custody and execution tools to support your research and trading workflow.

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