does the stock market go up or down fridays?
Does the stock market go up or down on Fridays?
Asking "does the stock market go up or down on Fridays" is a common way for investors to refer to the so‑called Friday effect or the broader weekend effect. This article explains what the phrase means, summarizes historical and modern evidence, compares equities with 24/7 crypto markets, and gives practical guidance for investors and traders who wonder whether calendar timing around Fridays is useful.
As of 2026-01-23, according to Investopedia and academic summaries, empirical evidence for day‑of‑week anomalies is mixed and often small after costs. 截至 2026-01-23，据 Investopedia 报道，本周末效应（Friday/weekend effect）在不同市场和时间段的强度各异。
Note: the phrase "does the stock market go up or down on Fridays" appears repeatedly in this article because it is the core search query many users enter. Readers will find a clear summary, methods used by researchers, representative study results, and practical points for trading or investing.
Definition and terminology
The query "does the stock market go up or down on Fridays" targets a set of calendar anomalies in equity markets. Common terms:
- Friday effect: the idea that returns realized on or around Fridays differ systematically from returns on other days.
- Weekend effect: a related observation that returns from Friday close to Monday open (or Monday close) differ from typical returns; often manifested as relatively weak Mondays and relatively strong Fridays.
- Monday effect: a specific form where Monday returns are abnormally low (or negative) relative to other weekdays.
Scope and measurement choices matter: researchers measure close‑to‑close daily returns, Friday afternoon intraday behavior (e.g., volume and price drift into the close), and gap returns from Friday close to Monday open. The query "does the stock market go up or down on Fridays" may thus mean: Are Friday close‑to‑close returns different? Do prices tend to run up into Friday close? Or do gaps occur after Friday close?
Important: equities trade during set market hours; crypto markets trade 24/7. Therefore, the mechanisms that create a Friday or weekend effect in stock markets (news clustering, information release schedules, weekend risk aversion) do not translate directly to crypto, which generally exhibits different seasonality patterns.
Historical background and discovery
The literature on day‑of‑week anomalies dates back decades. One of the early systematic descriptions is Frank Cross (1973), who documented weekday patterns in returns. Over the following decades, many studies reported evidence of a weekend effect—often described as negative average returns on Mondays and relatively higher returns on Fridays.
Empirical results have not been stable. Some studies found strong effects in early samples (pre‑1980s), weaker but present effects in later decades, and in recent years many researchers and backtests report that the effect has diminished or disappeared for large cap indices. Changes in market microstructure, after‑hours information dissemination, and widespread use of algorithmic trading are among the reasons proposed for attenuation.
Empirical evidence — summary of findings
Short answer to "does the stock market go up or down on Fridays": evidence is mixed. Some datasets and periods show slightly higher mean returns on Fridays or positive Friday→Monday return patterns, while other periods and instruments show no reliable effect. Key empirical points:
- Many early studies documented that Mondays underperformed and Fridays outperformed, on average. That pattern is one formulation of the weekend effect.
- Cross‑country studies show variation: some markets, especially less‑liquid or emerging markets, display stronger day‑of‑week effects than highly liquid developed markets.
- Firm characteristics matter: several studies report stronger weekend/Friday effects among small‑ and micro‑cap stocks than among large caps.
- Recent backtests focusing on liquid indices since the 2000s often find the effect is weak or not statistically significant after accounting for transaction costs, slippage, and changing volatility.
Researchers and financial media (Investopedia, Benzinga, FinanceWisePro, QuantifiedStrategies) consistently emphasize that the effect is small, inconsistent, and often not tradable for institutional investors once realistic trading costs are included.
Variation by market, time period, and firm characteristics
The answer to "does the stock market go up or down on Fridays" depends on which market and time period you examine:
- Country differences: some national equity markets show persistent weekday seasonality; others do not. Institutional structures, settlement calendars, and typical corporate news schedules alter patterns.
- Market capitalization: smaller firms historically show more pronounced weekday anomalies. Studies suggest that small‑cap stocks exhibit larger Friday/Monday differences than large‑cap indices.
- Historical period: evidence differs before and after major structural changes (e.g., decimalization in U.S. exchanges, increased electronic trading). Subsample analysis often shows stronger effects in older samples.
- Indices vs individual stocks: broad market indices smooth idiosyncratic events, while individual issues can show pronounced day‑of‑week variation due to scheduled news or concentrated retail trading.
These variations explain why aggregated headlines about "does the stock market go up or down on Fridays" are imprecise: the detailed answer depends on sample, time, and assets.
Representative pattern examples
- Pre‑1987 U.S. samples: stronger evidence for systematic Monday weakness.
- 1987–1998: mixed results; some attenuation.
- Post‑1998 / 2000s: many studies find smaller effects, especially for large cap indices.
Proposed explanations
Researchers and market commentators have proposed several explanations for why the calendar pattern might exist:
- Corporate news timing: firms (or regulators) might release bad news after the close on Friday to give markets more time to digest it, producing negative Monday returns and relatively better Fridays.
- Investor psychology: some investors reduce risk before weekends—profit‑taking or position squaring on Friday afternoons could push returns lower or create distinctive volume patterns.
- Short covering and position adjustments: fund managers and leveraged traders sometimes rebalance or close positions ahead of weekends to avoid overnight or weekend event risk.
- Liquidity and volume patterns: Friday afternoons tend to have distinctive liquidity profiles. Thin order books late on Friday can amplify price moves (Bookmap and trader commentaries document thinner, more one‑sided order flow into Friday close).
- Institutional scheduling: payrolls, settlement cycles, and fund rebalancing rules may create recurring flows tied to weekdays.
- Structural changes: algorithmic trading, improved information flow, and 24/7 news cycles have likely reduced the magnitude of traditional weekend anomalies.
No single explanation fully accounts for all findings; more likely, a combination of news timing, psychology, and liquidity creates intermittent weekend/Friday patterns that vary across markets and time.
Intraday Friday dynamics (Friday afternoon / close)
When people ask "does the stock market go up or down on Fridays," they sometimes mean intraday behavior into the Friday close. Practical observations include:
- Volume patterns: many markets show lower, or more irregular, trading volume in the late Friday session compared with mid‑week, depending on holidays and local market hours.
- One‑sided flow: traders who want to avoid weekend risk may reduce exposure late Friday, producing net selling or buying depending on positioning and recent performance.
- Price impact: thinner depth can lead to larger price moves from modest orders; Bookmap and trader analyses often note sharper intraday microstructure moves into Friday close.
These intraday features mean that even if average close‑to‑close Friday returns are not strongly positive, trading on Friday afternoons can be more costly or more volatile than mid‑week sessions.
Crypto markets vs stock markets
The question "does the stock market go up or down on Fridays" applies to equity markets with closed weekend sessions. Crypto markets operate 24/7, so the mechanisms that create Friday vs Monday gaps in equities (weekend accumulation of news) are less relevant.
Crypto seasonality studies document different patterns: weekday vs weekend volume shifts, intraday patterns by time zone, and retail trading spikes. However, because crypto prices continuously adjust around the clock, there are no systematic Friday → Monday gaps driven purely by market closure. Traders should not assume stock market weekend rules apply to crypto.
If you trade spot or derivatives and analyze seasonality, treat equity weekend studies and crypto seasonality studies as separate literatures.
Trading strategies and practical implications
Many retail and professional traders test simple calendar strategies motivated by "does the stock market go up or down on Fridays". Common tactic examples:
- Sell at Friday close and buy back at Monday open (capture positive Friday/negative Monday pattern).
- Buy at Friday close and sell at next open if backtests show Friday strength.
- Trade intraday Friday momentum (ride price moves into the close).
Lessons from research and backtests (QuantifiedStrategies, Benzinga, and Chase guidance):
- Any historical edge is typically small relative to realistic transaction costs and slippage.
- Execution and liquidity constraints make simple calendar strategies difficult for large funds.
- Data‑snooping and publication bias can exaggerate reported edges.
- Changing market structure and information flow reduce the likelihood that a past anomaly will persist.
For most long‑term investors, timing holdings around weekdays is unlikely to improve outcomes meaningfully. Short‑term traders who test Friday strategies should use realistic assumptions about costs, liquidity, and time subperiods.
When trading derivatives or leveraged products, be extra cautious: overnight and weekend event risk can dramatically change outcomes and margin requirements.
How researchers test the Friday/weekend effect
To answer questions like "does the stock market go up or down on Fridays", researchers use a range of empirical approaches. Key methodological choices include:
- Return definition: close‑to‑close daily returns, Friday close → Monday open gap returns, or intraday returns into the Friday close.
- Sample construction: index level vs individual stocks; inclusion/exclusion of delisted firms; treatment of corporate actions and dividends.
- Statistical tests: t‑tests for mean differences, ANOVA for weekday comparisons, regressions with day‑of‑week dummies controlling for firm fixed effects and volatility.
- Robustness: subperiod tests, cross‑country comparisons, and checks for heteroskedasticity and autocorrelation.
- Backtesting realism: include transaction costs, slippage, and realistic order execution modeling.
The ResearchSquare paper in the retained list highlights standard methodologies: t‑tests, ANOVA, and regressions with controls for firm size and volatility. QuantifiedStrategies emphasizes that once costs and slippage are added, historical edges often vanish.
Limitations, confounders and evolving market structure
Any answer to "does the stock market go up or down on Fridays" must account for limitations:
- Data‑snooping and publication bias: many tests are run and only significant findings are published; this inflates the appearance of anomalies.
- Changing market microstructure: electronic trading, algorithmic liquidity provision, and after‑hours information dissemination alter patterns over time.
- Globalization: markets around the world react to the same news faster than in past decades, reducing weekend information asymmetries.
- Confounders: macro events, holiday calendars, and earnings cycles can produce spurious weekday patterns if not controlled for.
Because of these factors, calendar effects that once seemed robust may be weaker or ephemeral in modern data.
Practical guidance for investors
If you are asking "does the stock market go up or down on Fridays" to decide whether to time your investing, consider the following practical points:
- Long‑term investors: Do not base portfolio allocation or buy/hold decisions on weekday timing. Diversification and asset allocation matter far more than weekday effects.
- Traders: If you plan to test Friday strategies, backtest using realistic costs, model intraday liquidity (especially Friday afternoons), and perform out‑of‑sample tests across multiple markets.
- Execution: For strategies that trade into Friday close or Monday open, be mindful of wider spreads and thinner depth; these increase realized trading costs.
- Risk management: Weekend event risk (corporate announcements, geopolitical news) can create material gaps; ensure position sizing and margin reflect that risk.
If you trade on a centralized exchange, consider execution and margin services from reliable, regulated platforms. When using Web3 wallets for crypto, prefer secure solutions; Bitget Wallet offers integrated custody and trading options for users who wish to interact with markets and wallets in a secure environment.
Representative empirical results (selected studies and summaries)
- Frank Cross (1973): Early documentation of weekday return patterns, motivating subsequent research into the weekend effect.
- Investopedia (overview): Summarizes the weekend effect, historical findings, and the idea that the effect has attenuated in recent decades. As of 2026-01-23, Investopedia notes mixed evidence across time and markets.
- ResearchSquare paper: Uses t‑tests, ANOVA, and regressions to compare Friday and Monday returns across samples; documents variation by firm size and market. The paper reports stronger effects among smaller firms and in certain historical subperiods.
- QuantifiedStrategies backtests: Finds that simple calendar strategies tied to Fridays or Mondays often produce weak raw returns and become unprofitable after realistic trading costs.
- Benzinga and FinanceWisePro: Popular press analyses emphasizing that day‑of‑week effects are variable and often too small to exploit for most traders.
- Bookmap blog and trader videos: Describe intraday liquidity and order‑book dynamics into Friday close—useful for execution‑focused traders.
- Medium analysis and other amateur data projects: Provide illustrative examples but are often limited by short samples or methodology choices.
Readers should treat single studies as informative but not definitive; meta‑analysis and multiple datasets provide stronger evidence.
How to interpret headline claims
When you see headlines answering the question "does the stock market go up or down on Fridays", ask:
- Which market and time period does the headline reference?
- Are returns reported raw or net of costs and slippage?
- Is the claim about intraday Friday behavior or Friday→Monday gaps?
- Is the finding robust across subsamples and control variables?
Careful reading of methods and samples is required to evaluate claims.
See also
- Monday effect
- Turn of the Month effect
- Intraday volatility patterns
- Seasonality in asset returns
References and further reading
Selected sources used to compile this article (no external links provided):
- Investopedia — "Understanding the Weekend Effect in Stock Markets" (overview and historical context).
- Benzinga — articles on day‑of‑week seasonality and trading‑day analyses.
- ResearchSquare — empirical paper comparing Monday vs Friday returns using t‑tests/ANOVA/regressions.
- FinanceWisePro — popular‑press treatment of Friday/weekend effects.
- SecureBizVest — blog post describing the Friday Effect and retail trading behavior.
- QuantifiedStrategies — backtests showing the weekend effect is weak/unstable in recent decades.
- Chase (consumer‑investor guidance) — advice that day‑of‑week timing is ineffective for most investors.
- Bookmap blog — intraday liquidity and Friday‑afternoon behavior analyses.
- Medium analyses and trader videos — illustrative data projects and practical trader commentary.
As of 2026-01-23, these sources generally report mixed evidence; headlines should be read in light of sample and method differences.
External data & tools
If you want to test "does the stock market go up or down on Fridays" yourself, consider these types of data and tools (generic descriptions only):
- Historical daily and intraday price data from reputable vendors and academic databases.
- Backtesting libraries that support intraday execution and transaction‑cost modeling.
- Order‑book visualization tools for intraday liquidity analysis (Bookmap‑style tools).
For crypto-specific seasonality tests, use continuous 24/7 price and on‑chain metrics (transaction counts, active wallets, staking flows) to differentiate from equity weekend dynamics.
Notes on scope and reliability
Empirical evidence addressing "does the stock market go up or down on Fridays" is mixed. Findings depend heavily on dataset, period, asset class, and methodology. Calendar effects are typically small and unstable; many reported anomalies vanish after accounting for realistic costs and modern market structure.
Practical next steps
- If you are a long‑term investor: focus on diversification, costs, and asset allocation rather than weekday timing.
- If you are a trader: develop robust backtests for any Friday‑based strategy and simulate realistic execution on Friday afternoons and Monday opens.
- If you trade crypto: do not assume equity weekend rules apply—analyze 24/7 patterns and on‑chain signals instead.
To explore execution, custody, and secure wallet options, consider Bitget services and Bitget Wallet for integrated trading and wallet management.
Further reading: consult the referenced studies and popular summaries listed above for methodological details and numerical backtest results. The question "does the stock market go up or down on Fridays" remains a useful starting point for investigation, but it is not a reliable shortcut to investment performance.
