Introducing the SPX 1DTE Bias Alert

The SPX 1DTE Bias Alert is now live inside the Alpha Crunching Discord.

This tool does not generate trades.
It does not predict price targets.

It answers one focused question:

When the market looks like this near the close, how often has it closed higher the next trading day?

For options traders, that context matters.

Why We Built It

Options trading is already built around probability.

Every credit spread, debit spread, and directional structure has an implied edge. The 1DTE Bias simply adds a historical market context layer to that decision.

It helps you evaluate:

• Is overnight exposure aligned with recent market structure?
• Are conditions historically supportive or unfavorable?
• Should I size normally, smaller, or not at all?

It doesn’t replace your strategy.
It helps frame the odds.

Especially Useful for PDT-Constrained Traders

Traders managing PDT limitations often rely on overnight positions instead of intraday trades.

But overnight risk comes with:

• Gap risk
• News risk
• Volatility shifts

The 1DTE Bias posts at 3:45pm ET, about 15 minutes before the close, giving you time to evaluate conditions before committing capital.

It won’t eliminate uncertainty — but it can help avoid leaning aggressively into statistically unfavorable environments.

How It Works (High-Level)

Each day at 3:45pm ET, the model classifies the market into a regime based on four dimensions:

1️⃣ Intraday Trend

Was today a sustained directional move or mostly chop?

2️⃣ Volatility Environment

Is volatility low, mid, or high relative to the past 63 trading days?

3️⃣ Range / Impulse

Was today’s move compressed, normal, or expanded compared to typical daily movement?

4️⃣ Close Location

Did price finish strong within the day’s range or not?

Once the regime is defined, we scan historical data for prior days that looked similar and measure:

How often did SPX close higher the next trading day?

That percentage becomes the 1DTE Bias probability.

Sample size is always shown for context.

Example: Higher Probability Environment

In this example, SPX closed higher 62% of the time under similar conditions — meaning it closed lower about 38% of the time historically.

That kind of reading may influence how aggressively you want to hold bullish overnight exposure.

What This Tool Is (And Is Not)

It is:

• A regime-based probability framework
• A contextual decision aid
• Designed for pre-close evaluation

It is not:

• A trading signal
• A prediction engine
• A substitute for risk management

Version 1 — And Improving

This is the first version.

We intentionally kept it:

• Transparent
• Simple
• Walk-forward tested
• Free of optimization loops

We’re already working on refinements for V2, including regime tuning and expanded statistical reporting.

But V1 gives us a clean, explainable foundation.

Final Thought

Markets are regime-driven.

Instead of asking “What will happen tomorrow?”
We ask:

What has usually happened next when the market looked like this?

For options traders already thinking in probabilities, that shift in framing can be powerful.

The SPX 1DTE Bias Alert posts daily at 3:45pm ET inside Discord.

It won’t tell you what to trade.
But it may help you align your trades with the historical odds.

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