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SPY 0DTE Decision Terminal

A read-only decision tool for same-day SPY options: one best opportunity, or an explicit no-trade.

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Same-day options punish hesitation and overtrading equally. The terminal answers one question in real time: what is the best opportunity right now, and why?

It turns market data into levels, dealer positioning, a regime and a bias, runs rule-based setup detectors, and returns a single decision with the conditions that confirm or invalidate it. It never places a trade, and no language model makes a decision.

Status
Internal alpha used for analysis on recorded and live market data. It has no order code, and production readiness is not established.
Stack
Python, FastAPI, Pydantic, pandas, SQLite, Lightweight Charts

Why it exists

Trading a same-day option means watching price, option quotes that can lag behind SPY and dealer hedging that can push the market around, all at once. A screen full of indicators leaves the decision to you at the moment it's hardest to make.

The terminal asks one question: what is the best opportunity right now, and why? The answer can be no trade, and it comes with a reason.

Try it

A synthetic session. Move the bias inputs and watch the decision change. This is an illustrative prototype built for this site with fictional data, not the product itself.

Decision terminal · Illustrative prototype · fictional data

One run through it

  1. Refresh

    Every twenty seconds, live data runs through the fixed pipeline.

  2. Wait for the range

    Opening ranges stay hidden until bars cover the full window, so nothing gets drawn from partial data.

  3. Stalk

    Setups that line up with the bias appear as stalking, capped at three.

  4. Check the trigger

    A trigger is only a candidate. Gates check data, bias, structure and dealer regime.

  5. Decide

    The result is an active setup with its conditions, or no trade with a reason. No order is ever sent.

What it does

  • Levels

    VWAP, the fifteen-minute opening range, premarket and prior-day highs and lows, ATR.

  • Dealer positioning

    From the same-day chain: the gamma flip, long or short gamma regime, and pressure zones where gamma concentrates.

  • A blended bias

    Four scored inputs combined with coverage, agreement and conflict into bullish, bearish, neutral or avoid.

  • Setup detectors

    Eight rule-based setups that move from stalking to triggered to invalidated or complete.

  • Live, replay, recon

    Run it live, replay a recorded session, or read the log of every state change.

  • Source health

    Each input is marked trusted, advisory or excluded, and a degraded banner says what is missing.

Why it's built this way

  • Recording that survives a crash

    A separate collector writes atomic checkpoints, so a killed run stays recoverable.

  • The backend owns the meaning

    Trust decisions live on the backend and JavaScript only renders, so Live and Replay always mean the same thing.

  • Ordered ranking, no mystery score

    Setups rank in a fixed order, so you can always see why one beat another.

How it fits together

  1. 01Fixed pipeline: provider, normalized data, levels, positioning, regime, bias, setups, decision.
  2. 02FastAPI and Pydantic on the backend; SQLite for recordings and replay.
  3. 03A plain JavaScript front end on TradingView Lightweight Charts. Red is reserved for invalidation.

In plain terms

SPY
A fund that tracks the S&P 500.
0DTE
An option that expires the same day. The name means zero days to expiration.
Option chain
All the contracts for an expiration, listed by strike price.
Gamma
How fast an option's price sensitivity changes as the market moves.
Dealer positioning
An estimate of the exposure market makers hold, since their hedging can move price.
Gamma flip
The strike where cumulative dealer gamma crosses zero.
Long or short gamma
Whether dealer hedging tends to dampen moves or amplify them.
VWAP
The day's average price, weighted by how much traded at each level.
Opening range
The high and low of the first minutes of the session.
ATR
Average true range, a measure of how far price typically moves per bar.
Setup
A rule-defined pattern with an entry, a stop and targets.
Stalking, triggered, invalidated
Waiting for the entry, confirmed at the entry, and stop traded.

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