Monatszyklus — ^GSPC

Seasonal intra-month progression without trend component. Above 50 = seasonally typical strong phase. Below 50 = seasonally typical weak phase.

Monthly Detail Table

Month	Avg Return	Median	Win Rate	n

Period	Month	Half	Avg Return	Win Rate	n

Calculations

• TDOM (Trading Day of Month) = sequential number of the trading day within the month (1, 2, 3, ...). Decoupled from calendar days — weekends and holidays are skipped.
• Intra-Month Curve: cumulative log-returns from last trading day of previous month (TDOM 0 = 0%). One curve per year, then averaged.
• Solid/Weak Split: TDOMs with n<10 observations are marked as a dashed red line (statistically uncertain).
• Detrend Indicator: Linear trend is subtracted, scaled to 0–100, midline=50. Above 50 = seasonally strong, below 50 = seasonally weak.
• Two-Week Split: Month divided into two halves at the selected TDOM (slider 5–15). 1st = TDOM 1..X, 2nd = TDOM X+1..end.
• Seasonal Match: Pearson correlation + DTW (Dynamic Time Warping) + t-test between current month progression and historical average.
• Presidential Cycle: Election year / Post-election year / Midterm year / Pre-election year according to formula ((year-2020)%4+4)%4+1.
• Momentum Check: conditional probability that the second half continues the sign of the first.