NET position, explained
NET POSITION is the dealer book in one number. Where dealers are short, retail is long — and the hedge flow follows.
NET POSITION is the headline metric on SPX-Flow — the yellow heatmap most users glance at first. It compresses the dealer book across the chain into one signed number per strike. Read this first every morning; it tells you the structural bias before any other metric speaks.
What it is
For each strike, NET POSITION is the dealer-held contracts net of customer-held contracts, signed and weighted. Positive means dealers own that strike. Negative means dealers wrote it. The useful property: dealers are the counterparty to retail. When dealers are net short, retail is net long. So the NET surface doubles as a strike-by-strike read on retail directional bias.
How you use it
The yellow NET POSITION heatmap (#fffb00) shows the dealer book across the chain. Look at the shape. Tight cluster around one strike: that’s the magnet — pin setup. One-sided NET, all negative on one wing: dealers are short there, retail is long, squeeze risk if price moves toward that wing. Cluster drifting across the session: the magnet is moving — early signal of a regime change, often visible 30–60 minutes before price catches up. Then overlay SPX price on the heatmap. Price tracking the cluster = pin holding. Price diverging = something is about to give.
Differentiated advantage
Most flow tools don’t separate dealer-side positioning from raw open interest at all. The few that do publish a single static EOD reading. SPX-Flow rebuilds NET every 10 minutes off OPRA-grade reconstruction, so the cluster you’re looking at is the dealer book as of the last refresh — and the drift across the session is preserved in replay.
Why you should care
NET is your fastest read on which side of the trade retail is on, and therefore which way dealer hedging will be forced if price moves. Most days the NET surface tells the whole story; the other metrics just add nuance. Skip NET and you’re trading without knowing where the structural pressure sits.
GEX deep dive
How to read the GEX heatmap on SPX-Flow — walls vs. accelerants, magnets vs. resistance, and why sign matters more than magnitude.
GEX on SPX-Flow is the gamma-exposure layer of the dealer book — rendered as the blue heatmap, refreshed every 10 minutes, with sign and intensity preserved at every strike. The trick to reading it is knowing what each color means.
What it is
Per-strike GEX is the dealer-held gamma exposure, signed by which side of the option dealers are on. Positive at a strike means dealers are long gamma there — they damp moves. Negative means short gamma — they amplify moves. The aggregate sum across the chain tells you the day’s regime; the per-strike map tells you where the action will happen.
How you use it
The blue GEX heatmap (#248aff) encodes both magnitude and sign. Positive intensity = wall. Dealers buy on dips and sell on rallies into that strike. Above spot it’s resistance (call wall); below spot it’s support (put wall); at spot it’s a magnet. Negative intensity = accelerant. Dealers sell into weakness and buy into strength. Once price breaches a negative-GEX strike, hedging compounds the move into a squeeze. Three patterns repeat: twin walls flanking spot (pin setup), one wall above with accelerant below (asymmetric, bias short), and walls migrating intraday (regime is shifting).
Differentiated advantage
A naive GEX chart shows magnitude as bars and forgets the sign. The SPX-Flow heatmap encodes both — positive and negative intensity render distinctly so you can see at a glance where price will be defended versus propelled. The 10-minute refresh also catches walls that are building or decaying, which a static EOD GEX number completely misses.
Why you should care
A wall isn’t always resistance. The same positive-GEX strike supports from below, resists from above, and magnetizes when spot is sitting on it. Get sign and location right and the trade is at the boundary between a defended strike and the next accelerant on the move side. Get them wrong and you’re fading a wall that doesn’t exist.
Understanding DEX
DEX fuses vanna and charm into one read of where dealer gamma is about to amplify, weaken, or flip.
DEX is the metric that doesn’t exist on any other options-flow product. It’s the second-order layer — vanna and charm fused into one intensity field — rendered as the purple heatmap. Where GEX shows static dealer gamma, DEX shows where that gamma is about to amplify or break.
What it is
DEX combines two second-order Greeks into a single per-strike intensity. Vanna is how delta changes when vol changes. Charm is how delta changes as time passes. Both force dealer hedging even when spot doesn’t move. DEX captures the total second-order pressure at each strike. When DEX intensifies, the hedging requirement at that strike is changing — and that change usually shows up in price 20-60 minutes later.
How you use it
The purple DEX heatmap (#b700ff) flags where gamma is about to amplify. Stack it with GEX and read the cross-pattern. High GEX wall + rising DEX at that strike: the wall is weakening, expect failure. Negative GEX accelerant + climbing DEX: the squeeze is loading, watch for the trigger. DEX–price divergence: price moves one way while DEX builds at strikes in the opposite direction — the cleanest reversal signal on the dashboard. DEX is unreliable in the first 15 minutes of the session and during the lunch hour (12:00-13:00 ET), where flow is too light to generate clean signal.
Differentiated advantage
Most flow products either ignore second-order Greeks entirely or surface vanna and charm as raw numbers buried in a sub-panel. DEX merges them into a primary metric on the main dashboard, with sign and intensity preserved across the chain. It’s the metric the agent leans on hardest for early regime calls.
Why you should care
GEX tells you the present hedging map. DEX tells you what’s about to happen to that map. If you’re only watching GEX, you see the current snapshot; you miss the transformation. The transformation is where the next move starts.
Vanna and VEX
VEX isolates the vanna component of dealer hedging. On vol-regime-shift days, it's the metric that explains everything else.
VEX (the orange heatmap) isolates the vanna piece of dealer hedging. Most days it sits quiet in the background. On days where VIX moves more than half a point, it becomes the most important metric on the dashboard.
What it is
Vanna is how delta moves when vol moves. When IV shifts, dealers’ effective deltas change without spot moving — and they have to re-hedge in the underlying to stay neutral. That forced flow is the vanna hedge, and on a vol-up or vol-down day it can dwarf the gamma hedge in size. The classic vanna rally: VIX prints down, dealers’ deltas shift positive, dealers buy SPX to neutralize, the buy flow lifts spot, vol drops further, the loop runs another cycle.
How you use it
The orange VEX heatmap (#ff6b35) shows where vanna hedging will concentrate at each strike. Positive at a strike means a vol-up move forces dealer buying there; negative means selling. Read it hard on three setups: VIX moves of 0.5+ points, macro event days (FOMC, CPI, NFP), and OPEX week into the close. On flat-vol days VEX is mostly noise — stack it with GEX to verify any read. Example: VIX prints down 0.8, VEX surges positive at strikes 5–10 points above spot, dealers buy in, price magnetizes upward.
Differentiated advantage
Vanna is the single most-ignored force in retail options-flow tools. SPX-Flow surfaces it as a first-class metric instead of folding it into GEX or burying it in a side panel. Combined with CEX and the merged DEX read, you get the full second-order picture — not just the gamma snapshot.
Why you should care
Most retail traders only realize the move that just happened was vanna after the fact. Pre-FOMC, post-CPI, opex Friday — these are the days where reading GEX alone leaves you blind. VEX lets you see the vol-driven hedge flow as it builds, not after it’s run.
Charm and CEX
CEX is the time-decay component of dealer hedging. By midday it usually points at the strike SPX wants to close near.
CEX (the cyan heatmap) is the time-decay piece of dealer hedging. It’s the slowest-moving metric on the dashboard and the most reliable for one specific job: forecasting the EOD pin. By 13:00 ET on most sessions, CEX is already pointing at the strike SPX wants to close near.
What it is
Charm is how delta moves as time passes. Even with spot and vol perfectly flat, dealers’ effective deltas shift every minute the clock ticks — and they have to re-hedge. That’s the charm flow. Charm scales roughly with 1/√T, which means it builds through the day and dominates the final 90 minutes. CEX measures that hedging sensitivity at each strike. The strike with peak intensity is the charm pin — where time decay is mechanically dragging price.
How you use it
The cyan CEX heatmap (#00e5ff) is your afternoon read. Mid-morning (10:30-11:00 ET): check it but don’t act — intensity is still building. Midday (12:30-13:30): identify the peak; that’s the candidate close. Afternoon (14:00-15:00): if SPX is drifting toward the peak with NET POSITION aligned, the EOD pin is on. Fade rallies above, fade dips below. Final hour: charm dominates. Unless a macro shock fires, price magnetizes to the peak with high reliability.
Differentiated advantage
Charm is invisible on every flow product that publishes only one snapshot per day. SPX-Flow’s 10-minute refresh shows the charm intensity build through the session, which is exactly when it matters. The peak is locked in by midday — earlier than most traders realize the close is already decided.
Why you should care
The EOD pin is the highest-frequency repeatable setup on SPX-Flow because the mechanic is so deterministic — the clock keeps moving, the hedging keeps firing, price keeps getting pulled. You don’t need to nail the open. Reading the CEX peak at 13:30 gives you a complete trade plan into the close, with two hours to enter.