SPX 0DTE: How Early in the Day Does the S&P 500 Pick Its Direction?

You glance at the S&P 500 during the session and it's green. Does that mean it will close green, or can it still flip by the end of the day? We tested this across 1,468 sessions from July 2020 through June 2026 by checking the index at every 15-minute interval.

With no VIX filter, a green reading at 9:30 AM held through the close 72% of the time. By noon, that rose to 81%, and by 2:30 PM it reached 88%. The later in the day you check, the more likely the current direction is to stick.

The same split, by VIX regime

Breaking the data down by VIX level reveals a clear shift in behavior. In low-volatility environments, green readings tend to persist while red readings often reverse higher. In high-volatility regimes, the pattern reverses: red readings become highly persistent, while green readings show little edge and hover near 50/50 through the morning. The table shows the percentage of same-color closes for each reading at each 15-minute interval.

No VIX Filter1,468 days

Time	Green	Red
9:30 AM	72.0%	68.1%
9:45 AM	72.5%	68.2%
10:00 AM	74.0%	69.9%
10:15 AM	75.9%	72.4%
10:30 AM	76.8%	72.8%
10:45 AM	78.1%	73.2%
11:00 AM	78.9%	74.4%
11:15 AM	80.2%	76.5%
11:30 AM	80.2%	77.1%
11:45 AM	80.5%	77.2%
12:00 PM	81.4%	79.4%
12:15 PM	81.6%	79.2%
12:30 PM	82.7%	80.1%
12:45 PM	83.4%	80.8%
1:00 PM	84.3%	81.7%
1:15 PM	84.7%	82.8%
1:30 PM	85.7%	83.4%
1:45 PM	86.0%	84.4%
2:00 PM	86.2%	83.8%
2:15 PM	86.9%	84.8%
2:30 PM	88.2%	86.2%
2:45 PM	88.5%	88.6%
3:00 PM	89.3%	89.7%
3:15 PM	90.2%	90.0%
3:30 PM	91.4%	89.8%
3:45 PM	94.0%	93.1%

VIX < 20868 days

Time	Green	Red
9:30 AM	74.5%	60.4%
9:45 AM	75.7%	60.2%
10:00 AM	76.9%	61.9%
10:15 AM	79.0%	64.3%
10:30 AM	80.8%	67.3%
10:45 AM	81.6%	66.6%
11:00 AM	83.4%	68.2%
11:15 AM	83.9%	70.5%
11:30 AM	83.8%	72.0%
11:45 AM	84.5%	72.8%
12:00 PM	84.5%	75.2%
12:15 PM	84.8%	74.9%
12:30 PM	85.8%	76.0%
12:45 PM	86.0%	75.9%
1:00 PM	86.9%	76.9%
1:15 PM	88.2%	78.7%
1:30 PM	89.0%	78.8%
1:45 PM	89.0%	81.1%
2:00 PM	89.1%	80.2%
2:15 PM	89.1%	80.4%
2:30 PM	90.5%	82.9%
2:45 PM	90.4%	86.1%
3:00 PM	91.6%	86.7%
3:15 PM	92.1%	87.1%
3:30 PM	91.8%	86.5%
3:45 PM	94.8%	91.3%

VIX 20-30520 days

Time	Green	Red
9:30 AM	70.1%	74.1%
9:45 AM	69.7%	75.1%
10:00 AM	71.6%	76.6%
10:15 AM	73.3%	80.2%
10:30 AM	71.9%	77.2%
10:45 AM	73.8%	78.7%
11:00 AM	74.2%	80.8%
11:15 AM	75.9%	81.9%
11:30 AM	75.8%	81.3%
11:45 AM	75.4%	80.6%
12:00 PM	77.6%	82.9%
12:15 PM	77.7%	82.0%
12:30 PM	78.9%	82.9%
12:45 PM	80.6%	84.8%
1:00 PM	81.1%	85.5%
1:15 PM	80.1%	86.3%
1:30 PM	81.1%	87.2%
1:45 PM	81.8%	86.6%
2:00 PM	82.1%	86.4%
2:15 PM	84.0%	88.3%
2:30 PM	85.0%	88.5%
2:45 PM	85.9%	89.9%
3:00 PM	85.6%	92.0%
3:15 PM	86.5%	92.1%
3:30 PM	89.8%	91.7%
3:45 PM	92.2%	94.3%

VIX > 3080 days

Time	Green	Red
9:30 AM	48.6%	90.7%
9:45 AM	48.7%	92.7%
10:00 AM	51.3%	95.1%
10:15 AM	51.4%	93.0%
10:30 AM	53.1%	89.6%
10:45 AM	59.4%	93.8%
11:00 AM	50.0%	89.1%
11:15 AM	57.6%	93.6%
11:30 AM	58.1%	91.8%
11:45 AM	58.1%	91.8%
12:00 PM	58.6%	90.2%
12:15 PM	61.3%	93.9%
12:30 PM	61.3%	93.9%
12:45 PM	63.3%	94.0%
1:00 PM	67.9%	94.2%
1:15 PM	65.5%	94.1%
1:30 PM	69.0%	96.1%
1:45 PM	69.0%	96.1%
2:00 PM	69.0%	96.1%
2:15 PM	71.4%	96.2%
2:30 PM	74.1%	96.2%
2:45 PM	75.0%	98.1%
3:00 PM	80.8%	98.1%
3:15 PM	87.5%	98.2%
3:30 PM	100.0%	100.0%
3:45 PM	95.5%	98.3%

Table	Green stays green	Red stays red
No VIX Filter
VIX < 20
VIX 20-30
VIX > 30

There's no need to memorize any of this. Our SPX 0DTE tool does all the calculations for you in real time, matching the live 15-minute checkpoint and VIX level to similar past days.

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