24/7 sessions

Definition

Crypto spot markets never close: no daily open or close, no weekend halt, no holidays, no opening or closing auctions (contrast ms-sessions-auctions). Every session-anchored habit from equities — the overnight gap, the close as the reference print, “before the open” event timing — either dissolves or inverts, and the mismatch between the 24/7 underlying and its exchange-hours regulated wrappers (ETPs, CME futures) creates structural gaps that are calendar facts, not surprises.

How it works / structure

• No canonical daily bar: “daily” candles are convention (most data vendors cut at 00:00 UTC); a strategy’s daily return series depends on the chosen cut, and replays must pin it (quant-data-hygiene).
• Wrapper hours vs underlying hours: spot ETPs trade US equity hours (crypto-etps); CME crypto futures trade nearly 24 hours on weekdays but halt weekends and observe CME holiday calendars (crypto-cme-futures). Weekend spot moves land on the wrappers as Monday gaps — the gap IS the weekend, priced at once.
• Event timing: macro releases (CPI, FOMC — event-cpi, event-fomc) hit crypto in real time like FX, including when US equity markets are shut; crypto-native events (protocol upgrades, exchange incidents) respect no calendar at all.
• Liquidity is not uniform: 24/7 access does not mean 24/7 depth — weekend and off-hours books thin measurably, and large moves have repeatedly clustered in thin-liquidity windows (documented venue outage and flash-move episodes; labeled: venue and industry post-mortems, not peer-reviewed).

When it applies

Backtest and replay design (bar-cut pinning, weekend handling, wrapper-vs-spot alignment), risk monitoring cadence (a book with crypto exposure has no “market’s closed” state — alerting and management rules must state their clock), event theses around weekend/holiday windows where the wrapper is shut, and any comparison of crypto vol/returns to equity series, where session mismatch alone creates artifacts.

Risk profile & failure modes

• Unmanaged weekend exposure: stop and hedge logic that lives on exchange-hours wrappers cannot act while spot moves through the weekend; Monday’s fill can be far through the intended level (mgmt-stop-loss assumptions break).
• Thin-window whipsaw: off-hours flash moves through stops in thin books, then retrace — a documented crypto pattern that session-agnostic backtests underweight.
• Bar-cut artifacts: strategy results that change with the daily cut are artifacts, not edge; the platform treats cut-sensitivity as a red flag in replay review.
• Operational fatigue: continuous markets push discretionary processes toward missed events or overtrading — process rules (disc-trading-plan) matter more, not less.

Evidence & limits

Wrapper trading hours are exchange-documented; the 24/7 underlying vs exchange-hours wrapper mismatch is discussed in the SEC’s own approval order. Off-hours liquidity thinning is consistently reported in industry market-quality studies but lacks a single canonical peer-reviewed citation — labeled accordingly. No claim is made that any particular window is systematically profitable or unprofitable.

Falsifiable-thesis examples

Illustrations only, not signals:

• “The spot ETP’s Monday opening gap exceeds 2% at least N times this quarter (weekend-risk thesis)” — falsified by the gap series.
• “Bitcoin’s realized volatility in the 00:00-06:00 UTC window runs below its 12:00-18:00 UTC window this quarter (liquidity-cycle thesis)” — falsified by the intraday vol series with a pinned bar cut.

Cross-references

• The equity baseline it breaks: ms-sessions-auctions
• The wrappers with hours: crypto-etps, crypto-cme-futures
• Structure and depth: crypto-spot-market-structure, ms-liquidity; replay discipline: quant-backtest-hygiene, quant-data-hygiene