Education
Do Bonds Lead the Stock Market? Only Under Stress — 50 Cases Since 2002
A flight into long-dated Treasuries and what the S&P 500 does next: 50 cases since 2002 give +2.09 % in two weeks, but only in volatile markets.
September 22, 2026
TLT
Education
Eleven Market Rules, Measured — Four Do Not Hold
September the crash month? Factor 1.059 at p = 0.127. Eleven market rules measured on historical price data, each with question, result and data basis.
September 22, 2026
SPY
Education
Pinning on Expiration Day: +0.35 Percentage Points Over 30 Years — and Growing
Do stocks close near a strike more often on expiration Friday? 158 names, 30 years, 41,203 observations: 6.88 % versus 6.53 %, p = 0.0050.
September 22, 2026
SPY
Education
Is the effect real? P-values on six of our own studies
p = 0.127 is not "no effect", p = 0.0050 is not "tradable". P-values explained on published studies, plus multiple testing and one error of our own.
September 22, 2026
SPY
Education
Does Bitcoin Lead the Stock Market? 12 Years and 3,020 Trading Days
Does Bitcoin lead the stock market? Twelve years of data show the link is same-day. Only very large crypto rallies leave a measurable trace in SPY.
September 21, 2026
BTC-USD
Education
Monthly 10 Strategy Backtested: 32 Years of SPY, 10 Trading Days a Month
Monthly 10 strategy backtested over 32 years: half the volatility, half the return, and the gains come from mid-month rather than the turn of month.
September 17, 2026
SPY
Education
Vol Regime Radar: How to Read Risk Reversal, IV Rank and IV Percentile
Risk reversal, IV rank and IV percentile made simple: read the SeasonAlpha vol regime radar and tell expensive volatility from cheap.
September 6, 2026
SPY
Education
Congress Stock Trading Tracker: What Nancy Pelosi & Co. Actually Trade
Congress stock trading tracker: what Nancy Pelosi & Co. trade under STOCK Act disclosures, how to read the filings — and why it is not a signal.
September 5, 2026
BE
Education
The Pre-FOMC Drift: Why the 24 Hours Before Fed Decisions Deliver a Large Share of Stock Returns
Pre-FOMC drift explained: why the 24 hours before Fed decisions deliver outsized stock returns — the research, real SPY numbers, and the limits.
September 3, 2026
SPY
Education
The DAX in September: Statistically Significant Weakness — The Significance Test Explained
Is the DAX really significantly weak in September? Avg −1.55%, p=0.0241 — and how the t-test, p-value and effect size separate a real effect from noise.
August 24, 2026
^GDAXI
Education
The OPEX Cycle: How Options Expiration Structures the Trading Month
The OPEX cycle explained: the four phases of options expiration, the pre-OPEX drift, the pin and the volatility window afterward — mechanics, not a signal.
August 8, 2026
SPY
Education
Dealer Positioning Explained: How Gamma, Vanna and Charm Drive Seasonality
Dealer Positioning made simple: gamma, vanna and charm reveal why the OPEX effect exists. Turn the seasonal pattern into the mechanism behind it.
August 2, 2026
SPY
Education
Long Gamma vs. Short Gamma: The Regime That Decides Market Volatility
Long gamma vs. short gamma made simple: why the gamma regime decides whether markets are calm or wild — and what the zero-gamma flip means for fragility.
August 2, 2026
SPY
Education
The Third-Friday Effect: Why the S&P 500 Opens Differently on Options Expiration
OPEX effect on the S&P 500: on the third Friday the market opens 18.5 basis points higher on average (Baltussen 2024). The mechanism behind the spike.
August 2, 2026
SPY
Education
Pinning Explained: Why Stock Prices Cling to Strikes on Expiration Day
Pinning explained: why stock prices cling to strikes at options expiry and how to read the call wall and put wall — backed by peer-reviewed JFE research.
August 2, 2026
SPY
Education
What Machine Learning Finds in 30 Years of Market Data — and Why the Bear Regime Surprises
KMeans and logistic regression on 30 years of market data: the bear regime delivers the highest Sharpe — and the DAX beats the SPY under an ML filter.
July 31, 2026
^GDAXI
Education
8 of 9 Sector ETFs Light Up Green: What 25 Years of Research Says About April, November and December
Nine US sector ETFs, 25 years of data: in April, November and December almost all show significantly positive returns. We cross-check with our own data.
July 31, 2026
XLK
Education
Sell in May, Then Bonds Instead of Cash: What 2025 Research Recommends
Sell in May with bonds instead of cash: a 2025 study plus our own 20-year cross-check on SPY and TLT show when the summer rotation actually pays off.
July 31, 2026
TLT
Education
The Turn-of-Month Effect Has a Timing Problem — and a Down Month Solves It
SPY turn-of-month over 15 years: after a negative month the average trade return rises from 0.75% to 1.25% — with a smaller maximum drawdown.
July 31, 2026
SPY
Education
The Independence Day Effect: Why the Nasdaq Rises Around July 4th
Around July 4th the Nasdaq 100 (QQQ) historically gained +1.47 % on average — in 70 % of years and statistically significant. The holiday effect in numbers.
July 1, 2026
QQQ
Education
The Second Half of the Year in Stocks: What H2 Seasonality Really Shows
How does the second half of the year unfold in stocks? 56 years of S&P 500 and 38 years of DAX data show a weak Q3, then one of the most reliable Q4 rallies.
June 27, 2026
^GSPC
Education
The Worst Month for the DAX: What 38 Years of Seasonality Reveal
Which month is historically weakest for the DAX? 38 years of data reveal a clear loser — and the strongest months across the year.
June 15, 2026
^GDAXI
Education
The Turn-of-the-Month Effect: Declared Dead — Yet Alive (in the Right Window)
New 2026 research and our own data show the turn-of-the-month effect isn't dead — it just changed its time window. What that means for investors.
June 14, 2026
^GSPC
Education
DAX vs. S&P 500: Which Index Is More Seasonal?
DAX or S&P 500 — which index shows stronger seasonal patterns? 35 years of data, month by month comparison. The differences are surprising.
May 14, 2026
^GDAXI
Education
Turn-of-Month Effect Explained: Why the Last 3 and First 3 Days of the Month Are Different
The Turn-of-Month Effect: Why the last 3 and first 3 trading days statistically outperform — with 30 years of S&P 500 data and explanation.
April 9, 2026
^GSPC
Education
Anomaly Radar Explained: Why SAP Can Be 'Normal' Despite a −28 % Chart
The Anomaly Radar shows a score of 24/100 (Normal) for SAP — even though the price is 28 % below the historical average. Here's why Z-score and percentile rank actually get this right.
April 8, 2026
SAP
Education
Understanding Drawdown: What Crash Years Reveal About the Market — and How Long Recovery Really Takes
What is a drawdown? 130 years of Dow Jones show: how deep do markets really fall, how long does recovery take — and which crash years were the worst?
April 1, 2026
^DJI
Education
Return Rises, Drawdown Falls — How Do Both Fit Together? A Look Under the Hood
Return rises, drawdown falls — a contradiction? 130 years of Dow Jones show why both can be true simultaneously and what it means for investors.
April 1, 2026
^DJI
Education
Welcome to SeasonAlpha.ai — Your Unfair Edge in the Stock Market
SeasonAlpha.ai is live! Discover the platform for data-driven seasonal market analysis — with 130 years of history, AI models, and interactive charts.
March 27, 2026
^DJI
Education
What Is Seasonality? A Guide for Traders and Investors
Seasonality in the stock market explained: Why patterns like Sell in May or the January Effect repeat — with 130 years of data and concrete examples.
March 27, 2026
^DJI