Last 59 trading days. "Overnight" = today's Open vs the PRIOR day's Close
(the same move plotted as the pink dotted line on the chart) — each day's own Open→Close
move is not counted here. Overnight $/% is what you'd have earned holding only from close
to next open; Cum. Index is the running compounded value shown on the chart's pink line.
Date
Prior Close
Overnight $
Overnight %
Cum. Index
Open
High
Low
Close
2026-07-17
$750.72
-8.64
-1.15%
$742.08
$742.08
$747.29
$740.80
$743.29
2026-07-21
$743.29
+3.00
+0.40%
$745.08
$746.29
$749.04
$744.19
$748.28
2026-07-22
$748.28
-1.66
-0.22%
$743.42
$746.62
$750.02
$746.37
$747.41
2026-07-23
$747.41
-8.04
-1.08%
$735.43
$739.37
$742.56
$735.21
$738.18
2026-07-24
$738.18
+0.33
+0.04%
$735.75
$738.51
$743.72
$737.29
$738.93
2026-07-27
$738.93
+5.98
+0.81%
$741.71
$744.91
$745.53
$735.87
$739.09
2026-07-28
$739.09
+0.10
+0.01%
$741.81
$739.19
$742.79
$735.98
$740.86
2026-07-29
$740.86
-0.89
-0.12%
$740.92
$739.97
$742.67
$729.10
$729.46
2026-07-30
$729.46
+6.59
+0.90%
$747.61
$736.05
$742.45
$734.59
$741.69
2026-07-31
$741.69
+2.99
+0.40%
$750.62
$744.68
$748.89
$737.68
$747.03
2026-08-03
$747.03
+2.41
+0.32%
$753.05
$749.44
$758.58
$748.80
$757.67
2026-08-04
$757.67
+2.96
+0.39%
$755.99
$760.63
$773.41
$760.52
$771.33
2026-08-05
$771.33
+4.52
+0.59%
$760.42
$775.85
$776.85
$769.52
$769.79
2026-08-06
$769.79
+0.42
+0.05%
$760.83
$770.21
$771.82
$767.46
$768.56
2026-08-07
$768.56
+2.46
+0.32%
$763.27
$771.02
$773.91
$769.61
$773.26
2026-08-10
$773.26
-0.66
-0.09%
$762.62
$772.60
$775.03
$771.89
$773.03
2026-08-11
$773.03
+1.50
+0.19%
$764.10
$774.53
$774.61
$769.34
$770.56
2026-08-12
$770.56
+4.15
+0.54%
$768.21
$774.71
$774.87
$771.29
$772.49
2026-08-13
$772.49
+2.38
+0.31%
$770.58
$774.87
$779.37
$774.11
$777.88
2026-08-14
$777.88
+0.66
+0.08%
$771.23
$778.54
$778.80
$775.43
$776.34
2026-08-17
$776.34
-0.16
-0.02%
$771.07
$776.18
$776.77
$772.51
$772.67
2026-08-18
$772.67
-3.97
-0.51%
$767.11
$768.70
$769.50
$766.92
$767.45
2026-08-19
$767.45
+2.91
+0.38%
$770.02
$770.36
$772.47
$768.11
$769.06
2026-08-20
$769.06
-3.10
-0.40%
$766.92
$765.96
$768.15
$762.05
$762.60
2026-08-21
$762.60
+3.45
+0.45%
$770.39
$766.05
$767.85
$764.17
$765.72
2026-08-24
$765.72
-0.94
-0.12%
$769.44
$764.78
$765.22
$762.08
$763.47
2026-08-25
$763.47
+2.69
+0.35%
$772.15
$766.16
$766.78
$763.05
$765.91
2026-08-26
$765.91
-1.18
-0.15%
$770.96
$764.73
$767.35
$763.93
$766.08
2026-08-27
$766.08
+2.42
+0.32%
$773.40
$768.50
$772.36
$767.16
$771.10
2026-08-28
$771.10
+0.66
+0.09%
$774.06
$771.76
$775.29
$768.31
$769.35
2026-08-31
$769.35
-2.02
-0.26%
$772.03
$767.33
$768.00
$764.72
$767.05
2026-09-01
$767.05
-5.04
-0.66%
$766.95
$762.01
$764.67
$759.48
$761.78
2026-09-02
$761.78
+0.67
+0.09%
$767.63
$762.45
$766.43
$761.73
$765.16
2026-09-03
$765.16
+2.74
+0.36%
$770.38
$767.90
$774.03
$767.45
$773.17
2026-09-04
$773.17
-1.16
-0.15%
$769.22
$772.01
$772.87
$769.00
$770.19
2026-09-08
$770.19
-1.12
-0.15%
$768.10
$769.07
$769.70
$765.15
$765.96
2026-09-09
$765.96
-1.88
-0.25%
$766.22
$764.08
$764.47
$760.94
$762.40
2026-09-10
$762.40
-4.37
-0.57%
$761.83
$758.03
$760.09
$756.64
$757.83
2026-09-11
$757.83
+6.89
+0.91%
$768.75
$764.72
$766.37
$763.60
$764.29
2026-09-14
$764.29
-5.29
-0.69%
$763.43
$759.00
$763.52
$757.93
$760.88
2026-09-15
$760.88
-0.76
-0.10%
$762.67
$760.12
$760.34
$756.15
$757.39
2026-09-16
$757.39
+2.11
+0.28%
$764.79
$759.50
$761.65
$749.60
$754.05
2026-09-17
$754.05
+9.10
+1.21%
$774.02
$763.15
$763.57
$759.96
$762.60
2026-09-18
$762.60
-1.29
-0.17%
$772.71
$761.31
$762.00
$757.97
$761.69
2026-09-21
$761.69
+4.56
+0.60%
$777.34
$766.25
$774.89
$766.03
$773.50
2026-09-22
$773.50
+0.53
+0.07%
$777.87
$774.03
$775.14
$772.57
$773.38
2026-09-23
$773.38
-0.59
-0.08%
$777.28
$772.79
$773.05
$766.50
$767.81
2026-09-24
$767.81
-3.74
-0.49%
$773.49
$764.07
$768.95
$763.25
$767.18
2026-09-25
$767.18
+1.60
+0.21%
$775.10
$768.78
$772.28
$766.29
$771.35
2026-09-28
$771.35
-3.00
-0.39%
$772.08
$768.35
$769.54
$763.72
$765.61
2026-09-29
$765.61
+1.22
+0.16%
$773.32
$766.83
$766.98
$762.35
$764.20
2026-09-30
$764.20
+2.25
+0.29%
$775.59
$766.45
$769.41
$762.18
$762.63
2026-10-01
$762.63
+1.73
+0.23%
$777.35
$764.36
$765.65
$758.79
$763.99
2026-10-02
$763.99
+6.59
+0.86%
$784.06
$770.58
$772.65
$767.14
$769.64
2026-10-05
$769.64
+0.05
+0.01%
$784.11
$769.69
$776.61
$769.63
$774.83
2026-10-06
$774.83
+3.32
+0.43%
$787.47
$778.15
$781.62
$777.96
$779.09
2026-10-07
$779.09
-3.32
-0.43%
$784.11
$775.77
$779.10
$773.61
$777.22
2026-10-08
$777.22
-2.36
-0.30%
$781.73
$774.86
$777.09
$770.43
$773.93
2026-10-09
$773.93
+2.31
+0.30%
$784.06
$776.24
$779.42
$775.14
$778.57
📈 Overnight % Gain Trend
Cumulative overnight-only return, indexed to 0% on 2026-07-16
(same window as the chart overlay and table above, just plotted as % instead of $).
🗓️ Overnight End-of-Month PnL
One checkpoint per calendar month (value at the last trading day seen that month) from the
same overnight-only cumulative series above. The first and last
month shown may be partial if the data window doesn't start/end on a month boundary.
Month
Start Value
End Value
PnL $
PnL %
2026-07
$750.72
$750.62
-0.10
-0.01%
2026-08
$750.62
$772.03
+21.40
+2.85%
2026-09
$772.03
$775.59
+3.56
+0.46%
2026-10
$775.59
$784.06
+8.47
+1.09%
📅 Seasonality — Close Price by Year
Each line is one calendar year's close price (or % change from that year's first trading
day, in "% from Jan 1" mode), aligned by month/day so the same point in the calendar lines
up across years. Most recent year is drawn thicker. Click a year in the legend to hide/show it.
🌙 Overnight vs. Intraday Return
Overnight (close→next open) Intraday (open→close)
From 2016-01-04 to 2026-08-21 (2,666 trading days), $1 invested
overnight-only would now be worth $2.68;
$1 invested intraday-only would be worth $1.68.
SPY's historical return has leaned mostly on the overnight session.
This reflects a statistical pattern in past prices, not a trading strategy or investment advice —
it ignores transaction costs and slippage.
🎯 Best Strategy Backtest
See which saved strategy has the best real backtested win-rate on SPY, with buy/sell triggers plotted right on the chart.