Continuous FX auctions, session-cuts, and gap proxies

Daily OHLC is a session-cut

A continuous currency session has no exchange close, so a daily OHLC bar is built by assigning an arbitrary hour as open and close. That hour is the session-cut: the clock a charting package uses to end one daily bar and start the next in a market that does not halt.

The bar that results is a synthetic-daily, a 24-hour currency bar whose open and close are assigned by software rather than by an exchange close. Charting packages do not share a standard daily session-cut, so daily charts of the same pair and span can look materially different.

Pattern rules follow the vendor clock

On one same-span EUR/USD daily comparison, a hammer at support is clear on one package's bar and far less significant on the other. Highs and lows on many bars do not match. A pattern entry taken from one vendor's synthetic-daily can be absent from another vendor's daily of the same market.

Without a standard daily chart, the shared-attention edge that comes from many participants watching identical daily bars is not available in foreign exchange. A shared-chart is a price depiction many desks see identically, so pattern levels can coordinate. The synthetic-daily does not supply that common picture.

Hourly structure as the shared-chart

A nonstop auction rarely prints close-to-open gaps, so tactics that need a gap as an emotional extreme do not transfer as bar-to-bar discontinuities. Gap-inventory is the untraded span created when a session opens away from the prior close, and a continuous auction rarely leaves that span.

Hourly EUR/USD charts from different packages stay similar enough to serve as a common price depiction for pattern work. The hourly clock is monitored from interbank desks through individual traders, which is why that timeframe is treated as a more reliable shared map than the synthetic-daily.

A daily chart can still be scanned for candidate setups, but hourly structure is used to locate the pivot levels that define an executable entry. Wide-range hourly bars can stand in for gaps. A wide-range-bar is an unusually large hourly range used as a stand-in for the one-sided auction that a gap would print after a close. On USD/JPY, price later retraces into those bars the way equity prices fill a gap.