Premarket levels are the most important reference points for day traders. The PM HOD (premarket high of day) and PM LOD (premarket low of day) define the range of trading activity before the 9:30 AM ET open. These levels are established during extended hours trading, typically between 4:00 AM and 9:30 AM ET using SIP (Securities Information Processor) feed data.
Range interpretation is critical for selecting which stocks to trade. A tight premarket range (less than 1% of stock price) suggests that the stock has not yet made its move, creating potential for a directional breakout at the open. A wide premarket range (greater than 2-3%) suggests the move may be exhausted, with the stock more likely to chop within the established range. The ideal setup is a moderate gap with a clean, defined range.
When scanning for premarket levels, you want to focus on stocks with unusual premarket volume, a clear gap from the previous close, and identifiable HOD/LOD levels. The scan should filter for minimum gap percentage (typically 2%+), minimum premarket volume, and stocks with options liquidity if you plan to trade 0 DTE contracts. Earnings, FDA decisions, and macro events are common catalysts that create tradeable premarket ranges.
One important nuance: the SIP feed aggregates early premarket activity into the first reported bar (typically at 08:00 UTC / 4:00 AM ET). This means you must scan all available bars to find the true PM HOD and PM LOD, not just look at the most recent bar. Using only the last bar can cause you to miss extremes that were established earlier in the session, leading to incorrect level placement.