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
Open
High
Low
Close
Prior Close
Overnight $
Overnight %
Cum. Index
2026-06-09
$743.63
$746.90
$722.59
$737.05
$739.22
+4.41
+0.60%
$743.63
2026-06-16
$754.55
$755.44
$749.88
$750.33
$737.05
+17.50
+2.37%
$761.29
2026-06-17
$751.29
$752.15
$739.22
$740.96
$750.33
+0.96
+0.13%
$762.26
2026-06-18
$747.76
$748.23
$743.86
$746.74
$740.96
+6.80
+0.92%
$769.26
2026-06-22
$747.70
$750.18
$743.13
$744.39
$746.74
+0.96
+0.13%
$770.24
2026-06-23
$733.81
$739.63
$732.30
$733.58
$744.39
-10.58
-1.42%
$759.30
2026-06-25
$738.91
$739.35
$729.60
$734.30
$733.58
+5.33
+0.73%
$764.81
2026-06-26
$728.95
$736.53
$726.86
$728.99
$734.30
-5.35
-0.73%
$759.24
2026-06-29
$736.52
$741.56
$732.11
$741.00
$728.99
+7.53
+1.03%
$767.08
2026-06-30
$741.29
$748.02
$740.89
$746.77
$741.00
+0.29
+0.04%
$767.38
2026-07-01
$745.00
$749.43
$742.38
$745.76
$746.77
-1.77
-0.24%
$765.57
2026-07-02
$747.40
$751.31
$740.03
$744.78
$745.76
+1.64
+0.22%
$767.25
2026-07-07
$750.22
$750.96
$745.21
$747.71
$744.78
+5.44
+0.73%
$772.85
2026-07-08
$743.16
$746.14
$739.51
$745.40
$747.71
-4.55
-0.61%
$768.15
2026-07-09
$747.35
$751.97
$745.59
$751.71
$745.40
+1.95
+0.26%
$770.16
2026-07-10
$752.05
$755.42
$748.10
$754.95
$751.71
+0.34
+0.05%
$770.51
2026-07-13
$752.47
$753.91
$748.03
$749.17
$754.95
-2.48
-0.33%
$767.98
2026-07-14
$750.91
$753.30
$748.66
$751.83
$749.17
+1.74
+0.23%
$769.76
2026-07-15
$754.24
$755.58
$750.20
$754.81
$751.83
+2.41
+0.32%
$772.23
2026-07-16
$752.76
$754.57
$747.89
$750.72
$754.81
-2.05
-0.27%
$770.13
2026-07-17
$742.08
$747.29
$740.80
$743.29
$750.72
-8.64
-1.15%
$761.27
2026-07-21
$746.29
$749.04
$744.19
$748.28
$743.29
+3.00
+0.40%
$764.34
2026-07-22
$746.62
$750.02
$746.37
$747.41
$748.28
-1.66
-0.22%
$762.64
2026-07-23
$739.37
$742.56
$735.21
$738.18
$747.41
-8.04
-1.08%
$754.44
2026-07-24
$738.51
$743.72
$737.29
$738.93
$738.18
+0.33
+0.04%
$754.78
2026-07-27
$744.91
$745.53
$735.87
$739.09
$738.93
+5.98
+0.81%
$760.89
2026-07-28
$739.19
$742.79
$735.98
$740.86
$739.09
+0.10
+0.01%
$760.99
2026-07-29
$739.97
$742.67
$729.10
$729.46
$740.86
-0.89
-0.12%
$760.07
2026-07-30
$736.05
$742.45
$734.59
$741.69
$729.46
+6.59
+0.90%
$766.94
2026-07-31
$744.68
$748.89
$737.68
$747.03
$741.69
+2.99
+0.40%
$770.03
2026-08-03
$749.44
$758.58
$748.80
$757.67
$747.03
+2.41
+0.32%
$772.52
2026-08-04
$760.63
$773.41
$760.52
$771.33
$757.67
+2.96
+0.39%
$775.54
2026-08-05
$775.85
$776.85
$769.52
$769.79
$771.33
+4.52
+0.59%
$780.08
2026-08-06
$770.21
$771.82
$767.46
$768.56
$769.79
+0.42
+0.05%
$780.51
2026-08-07
$771.02
$773.91
$769.61
$773.26
$768.56
+2.46
+0.32%
$783.00
2026-08-10
$772.60
$775.03
$771.89
$773.03
$773.26
-0.66
-0.09%
$782.34
2026-08-11
$774.53
$774.61
$769.34
$770.56
$773.03
+1.50
+0.19%
$783.85
2026-08-12
$774.71
$774.87
$771.29
$772.49
$770.56
+4.15
+0.54%
$788.08
2026-08-13
$774.87
$779.37
$774.11
$777.88
$772.49
+2.38
+0.31%
$790.50
2026-08-14
$778.54
$778.80
$775.43
$776.34
$777.88
+0.66
+0.08%
$791.17
2026-08-17
$776.18
$776.77
$772.51
$772.67
$776.34
-0.16
-0.02%
$791.01
2026-08-18
$768.70
$769.50
$766.92
$767.45
$772.67
-3.97
-0.51%
$786.95
2026-08-19
$770.36
$772.47
$768.11
$769.06
$767.45
+2.91
+0.38%
$789.93
2026-08-20
$765.96
$768.15
$762.05
$762.60
$769.06
-3.10
-0.40%
$786.75
2026-08-21
$766.05
$767.85
$764.17
$765.72
$762.60
+3.45
+0.45%
$790.31
2026-08-24
$764.78
$765.22
$762.08
$763.47
$765.72
-0.94
-0.12%
$789.34
2026-08-25
$766.16
$766.78
$763.05
$765.91
$763.47
+2.69
+0.35%
$792.12
2026-08-26
$764.73
$767.35
$763.93
$766.08
$765.91
-1.18
-0.15%
$790.90
2026-08-27
$768.50
$772.36
$767.16
$771.10
$766.08
+2.42
+0.32%
$793.39
2026-08-28
$771.76
$775.29
$768.31
$769.35
$771.10
+0.66
+0.09%
$794.07
2026-08-31
$767.33
$768.00
$764.72
$767.05
$769.35
-2.02
-0.26%
$791.99
2026-09-01
$762.01
$764.67
$759.48
$761.78
$767.05
-5.04
-0.66%
$786.78
2026-09-02
$762.45
$766.43
$761.73
$765.16
$761.78
+0.67
+0.09%
$787.48
2026-09-03
$767.90
$774.03
$767.45
$773.17
$765.16
+2.74
+0.36%
$790.30
2026-09-04
$772.01
$772.87
$769.00
$770.19
$773.17
-1.16
-0.15%
$789.11
2026-09-08
$769.07
$769.70
$765.15
$765.96
$770.19
-1.12
-0.15%
$787.96
2026-09-09
$764.08
$764.47
$760.94
$762.40
$765.96
-1.88
-0.25%
$786.03
2026-09-10
$758.03
$760.09
$756.64
$757.83
$762.40
-4.37
-0.57%
$781.52
2026-09-11
$764.72
$766.37
$763.60
$764.29
$757.83
+6.89
+0.91%
$788.63
📈 Overnight % Gain Trend
Cumulative overnight-only return, indexed to 0% on 2026-06-08
(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 %
2026-06
$739.22
$767.38
+28.16
+3.81%
2026-07
$767.38
$770.03
+2.65
+0.35%
2026-08
$770.03
$791.99
+21.96
+2.85%
2026-09
$791.99
$788.63
-3.36
-0.42%
🌙 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.