The cost of a single slip is twenty basis points. Volatility remains the primary driver of gap validity, as the notes at orb trading premarket smoothedgedesign describe. Measuring a gap against the average true range determines if a move is a momentum signal or an exhaustion signal during the premarket session. The ratio provides a mechanical filter for an opening range breakout.
The Mechanics of Gap Ratios
A gap size is measured by calculating the distance between the previous day's close and the current day's open. The average true range is then calculated over a specific timeframe. The ratio of the gap to the ATR provides the context. A ratio exceeding two times the ATR often signals exhaustion. This suggests the move has already absorbed the available liquidity. Conversely, a ratio between zero point five and one point five suggests momentum. This indicates the price has enough room to expand during the first hour of regular trading hours.
Identifying Exhaustion Signals
Exhaustion occurs when the gap exceeds the historical volatility limits. A large gap relative to the ATR often leads to a mean reversion toward the previous day's close. This typically happens during the first fifteen minutes after the market open. High ratios indicate that the overnight session has already pushed the price to an extreme. When the ratio is too high, the probability of a trend continuation decreases. The price often lacks the fuel to maintain the extension, resulting in a gap fill.
Momentum and Trend Continuation
Momentum signals appear when the gap size stays within a reasonable multiple of the ATR. A gap of one ATR provides the necessary impulse for a sustained move. Traders watch the five minute range to confirm if the initial thrust holds. If the price stays above the high of the opening bell, the momentum remains intact. This mechanical approach removes the guesswork from whether a gap represents a new trend or a climax. A steady ratio supports the validity of an intraday trend.
Volatility and Timeframe Selection
The ATR must be calculated using a consistent period to ensure accuracy. Using a fourteen day ATR is standard for most intraday setups. The ratio is applied to the opening range to determine the strength of the breakout. A large gap on low volume often fails to sustain the move through the thirty minute range. High volume paired with a moderate ATR ratio increases the likelihood of a successful opening range breakout. The math provides a boundary for expected price movement.
Execution and Data Consistency
Data errors occur when the overnight session data is not properly synced with the previous close. Precise measurement of the ATR is required to prevent false signals. A small sample overstates the edge if the ratio is not applied to a wide set of historical data. The calculation remains the same regardless of whether the analysis uses a 15 minute or 60 minute window. The ratio is the metric. The ATR is the baseline. The gap is the trigger.