What is the Swing Line?
The Swing Line is SquawkFlow's name for a price level that marks where a model says options-driven hedging shifts from damping moves to amplifying them. We define it structurally: the lowest strike between the put wall and the call wall where modelled net dealer gamma is positive. It is closely related to but distinct from the GEX flip. The GEX flip marks where total modelled dealer gamma crosses zero; the Swing Line is read off the strikes between the walls. Other providers publish similar lines and build them in different ways, some from second-order flows (vanna and charm), some structurally, as we do. The levels often sit close together but can diverge, and two providers' versions can differ from each other for the same reason.
How the Swing Line Works
The Swing Line captures the interaction between implied volatility and dealer hedging. When the underlying trades above the Swing Line, the model has dealers' hedging leaning against moves, the condition associated with lower realized volatility. Below it, the model has the hedging adding to moves, the condition associated with larger swings. Neither side of the level says which direction price goes. The Swing Line is the model's answer to one question: does the assumed options positioning lean against moves here, or add to them?
Swing Line vs. GEX Flip
Traders sometimes confuse these two levels, but they measure different things:
GEX flip: Where total dealer gamma crosses zero. This is a broad measure of directional hedging pressure.
Swing Line: Where a model says hedging shifts from damping moves to amplifying them. Ours is structural, the lowest positive-gamma strike between the walls. Similar lines elsewhere are sometimes built from second-order flows instead, vanna (sensitivity of delta to changes in IV) and charm (sensitivity of delta to time decay), which the simple GEX flip leaves out.
When price sits between the two levels, the two definitions disagree about which regime applies, so neither reading is strong. When price is well above both, both describe damping hedging; well below both, both describe amplifying hedging. That is agreement between two models built on the same open interest, not a measurement of what volatility will be.
Practical Application for Traders
The level is read by its distance from the current price, and it describes the modelled hedging, not the coming session:
Well above the Swing Line: The model has hedging leaning against moves with room to spare, so a modest move does not change the regime it describes.
Near the Swing Line: A small move can carry price across the line, so the regime the model describes can change within the session. Close to the line, the sign of the modelled hedging is also the least certain part of the model.
Below the Swing Line: The model has hedging adding to moves. That describes the character of a move once one starts, not whether one will start or which way it will go.
Combining the Swing Line with Other Levels
The Swing Line is usually read alongside the GEX flip, call wall, and put wall. When all four point the same way, that is consistency between outputs of one model built on one set of open interest, not independent confirmation. When they conflict, the model is telling you the regime is not resolved.
Monitoring on SquawkFlow
SquawkFlow publishes its modeled Swing Line alongside the other GEX levels computed from daily-settled open interest. The level carries its settlement date and does not update from intraday options trades.
The Swing Line tells you which side of a modelled threshold price sits on. It does not anticipate market swings, and its sign rests on the same unobserved dealer positioning as every other gamma level.