FTSE 100 Index Seasonality: Best and Worst Months, Weekly Trends, and Key Trading Patterns

Also about Seasonality:

Santa Claus Rally

Late December’s "Santa Claus Rally"—coincidence or strategy?

Commodities Seasonality

Explore the Seasonality of different Commodity classes.

Sell in May and go away

A Wall Street myth or a smart investing move?

Historical Patterns and Strategic Insights

The FTSE 100 index, a benchmark of the UK stock market, follows discernible seasonal trends influenced by corporate earnings cycles, investor sentiment, and global macroeconomic factors. Below is a comprehensive breakdown of the FTSE 100’s historical seasonality based on 5, 10, and 15-year data windows.

Monthly Seasonality: Cycles of Strength and Weakness

January – March: A Mixed Start to the Year

January: The year typically begins with a moderately bullish tone. Long positions have a success rate of 60% (5 years), 50% (10 years). However, over the long term, short trades gain traction with a 53% success rate (15 years).
February: Bullish momentum picks up. Long setups succeed 60% (5 years), 70% (10 years), and 80% (15 years), making it the strongest months in Q1.
March: The market starts to soften. Long positions hold at 60% (5 years) but drop to 50% (10 years) . While short trades become more prominent at 53% over 15 years.

April – June: Seasonal Peak and Turning point

April: Historically the strongest month for the FTSE 100. Long trades dominate with a 100% success rate (5 years), 90% (10 years), and 73% (15 years). April consistently offers the best long-side opportunities.
May: The bullish trend slows. Long setups succeed 80% (5 years), but drop to 60% (10 years) and 53% (15 years), signaling increased caution.
June: Short interest starts to rise across all timeframes at 60%.

July – September: A Gradual Bearish Shift

July: Strength briefly returns. Long trades perform well with 60% (5 years), 80% (10 years), and 73% (15 years) win rates.
August: Bearish tendencies emerge. Short positions win 60% (5 years and 10 years), and 67% (15 years), making August one of the more consistent months for short trades.
September: Weakness persists. Short trades succeed 60% of the time over a 5-year timeframe. Over 10- and 15-year timeframes, long trades slightly prevail with a 60% success rate.

October – December: Recovery and Year-End Strength

October: A transition month with mixed signals. Short trades show slight dominance with a 60% win rate (5 years), while long trades remain below average at 50% over 10 Years and 53% over 15 Years.
November: Recovery begins. Long trades succeed 80% (5 years), 50% (10 years), and 53% (15 years), showing solid bullish potential.
December: A traditionally bullish month. Long positions perform well with a 60% success rate (5 and 10 years) and 67% (15 years), often driven by year-end rallies and investor repositioning.

Weekly Seasonality FTSE 100: Strength Builds into the Weekend

The FTSE 100 exhibits subtle but meaningful patterns throughout the trading week. While no single day overwhelmingly dominates, some days offer slightly more favorable setups for long positions.

Monday: Starts the week on a neutral note. Long positions succeed 55% (5 years), 52% (10 years), and 51% (15 years). This makes Monday the most inconsistent day, with a gradual decline in long trade success over time.
Tuesday: Stability takes over. Long setups win 52% (5 and 10 years), and edge slightly higher at 53% over 15 years. A calm but unremarkable day for trading long.
Wednesday: Midweek brings slightly stronger momentum. Long trades win 55% (5 years), 56% (10 years), and 53% (15 years), making Wednesday one of the more favorable days historically.
Thursday: Momentum stalls. Long trades are successful only 51% (5 years), 50% (10 years), and 51% (15 years). Historically, Thursday appears to be the weakest day of the week for bullish trades.
Friday: The week closes with renewed strength. Long trades succeed 54% (5 years), 54% (10 years), and 53% (15 years), making Friday one of the more consistent bullish days.

Daily Seasonality: Key Trading Days

Certain individual dates in the FTSE 100 calendar have historically offered exceptionally strong setups for directional trades.

Best Long Trade – February 12th:
This date stands out as a statistically powerful day for long positions. Historical data shows a 100% success rate over the past 5 and 10 years, and 90% over 15 years, making it one of the most reliable bullish entries of the year.
Best Short Trade – February 18th:
For traders looking to capitalize on downward momentum, February 18th has historically been the most consistent day for short setups. It holds a 100% success rate for short trades over 5 and 10 years, and 80% over 15 years.