Order Flow
The real-time stream of buy and sell orders hitting the market — the raw aggression behind every candle, revealing who is in control before the chart shows it.
Order Flow is the study of actual transactions hitting the bid and ask — not just price, but WHO is buying, WHO is selling, and at what urgency. Every green or red candle on your chart is a compressed summary of thousands of individual orders. Order Flow decompresses that summary back into its raw parts.
Core concepts:
- ●Market orders (aggressive) cross the spread to buy the ask or sell the bid — they move price.
- ●Limit orders (passive) rest on the book and absorb aggression — they resist price movement.
- ●The tug-of-war between aggressive and passive flow at each price level is what produces the Footprint Candle, Imbalance, Absorption, and Delta readings that institutional desks monitor in real time.
Why SPX traders can't directly access it: SPX options trade on CBOE — a fragmented, electronic market with no centralized tape of every last fill the way equity futures (ES) provide through the CME. Raw Level II or Time & Sales data for SPX is either unavailable to retail or prohibitively expensive. This is not a minor detail — it means the canonical "watch the tape" order-flow workflow does NOT apply to SPX options as-is.
What SPXXL does instead: the engine reads the EFFECTS of order flow — momentum, compression, expansion ratios, VWAP bias, relative volume, and dealer Gamma positioning — to infer who is winning the aggression battle at the session level. Think of it as reading the weather by watching the trees bend, rather than measuring the wind directly.
For 0DTE traders: understanding Order Flow means understanding that price is not random — it is the visible result of a hidden aggression auction. Every SPXXL session classification is, at its core, a statement about which side won that auction today.
This entry is educational and uses SPX for illustration — it is not financial advice, and no outcome is predicted or guaranteed.
Related Terms
An advanced candle type that displays the volume transacted at each price level within the bar — showing the bid×ask split that a standard candle hides.
When price makes a new high (or low) but the cumulative Delta does not — a signal that the aggression behind the move is exhausting.
A lopsided ratio of buying-to-selling volume (or vice versa) at a specific price level — a signal that one side is overpowering the other.
When passive limit orders absorb aggressive market orders WITHOUT price moving — a hidden wall that reveals large institutional resting liquidity.
The dealer desks that quote and take the other side of SPX options trades — their delta and Gamma hedging of 0DTE flow is now one of the strongest forces shaping intraday SPX price action.
The aggregate Gamma positioning of options market makers — determines how dealer hedging amplifies or dampens SPX price moves.
The total number of option contracts traded during a given period — higher volume means more participants are actively buying and selling, which makes it easier to enter and exit positions at fair prices.