Friday the 13th and the Stock Market

Friday the 13th and the Stock Market: Insights and Superstitions

Friday the 13th has long been associated with bad luck, though the exact origin of the superstition is not known (to our knowledge). Those who grew up reading Donald Duck know the bad luck that happened on Friday the 13th. But is Friday the 13th an unlucky day?

Backtests reveal that Friday the 13th has historically been a better Friday than any random Friday!

Let’s look at the number, statistics, and performance on Friday the 13th. We ran some backtests:

What’s the origin of Friday the 13th?

Some say it may be linked to the story of Jesus’ last supper, which was held on a Friday and had 13 attendees. Friday has also been traditionally associated with bad luck in many cultures, which could have added to superstition.

Additionally, in the Middle Ages, Fridays were believed to be the day that witches gathered, which also could have contributed to the association with bad luck.

There are also a few theories about the number 13 itself. In Norse mythology, it was said that 12 gods were at a dinner table when Loki, the 13th guest, arrived and caused the death of Balder, the god of joy and gladness. In some interpretations of this story, 13 is seen as a symbol of chaos and disruption – unluck.

Additionally, the number 13 is sometimes seen as an unlucky number due to its association with a 13-year cycle in the Chinese calendar.

As you can see, there are many theories about the number 13. We are not superstitious and believe this is mumbo jumbo. But let’s backtest to look at the data and facts.

How do stocks perform on Friday the 13th?

Friday the 13th and Stock Market Performance

It’s straightforward to write the code for Friday the 13th. If we put the code into Amibroker and backtest the performance from the close of Thursday until the close of Friday the 13th, we get the following equity curve for S&P 500 since 1960:

There are only 107 trades since 1960 but the average gain is 0.13% – way higher than any typical trading day. The results may be compared to this:

  • The average gain from close to close since 1960 is 0.03% on any random day of the week.
  • The average gain on any Friday since 1960 has been a positive 0.03%.

This is the equity curve of being invested from the close of any Thursday until the close of Friday since 1960:

More seasonal trading strategies

We have plenty of similar seasonal trading strategies like Friday the 13th:

List of trading strategies

We have written over 1000 articles on this blog since we started in 2012. Many articles contain specific trading rules, like this article, that can be backtested for profitability and performance metrics.

The code for the backtested Friday the 13th trading strategy is included in the package.

The trading rules are compiled into a package where you can purchase all of them (recommended) or just a few of your choice. We have hundreds of trading ideas in the compilation.

The strategies are taken from our source of what are the different types of trading strategies. The strategies are an excellent resource to help you get some trading ideas.

The strategies also come with logic in plain English (plain English is for Python traders).

For a list of the strategies we have made please click on the green banner:

These strategies must not be misunderstood for the premium strategies that we charge a fee for:


What are the origins of the superstition surrounding Friday the 13th?

The superstition may be linked to Jesus’ last supper, which had 13 attendees and occurred on a Friday. Additionally, cultural beliefs about Fridays being unlucky and associations with witches gathering on Fridays contribute to the superstition.

How does the stock market perform on Friday the 13th?

Norse mythology tells a story of 13 being associated with chaos and disruption, and the Chinese calendar’s 13-year cycle is considered unlucky. Despite these theories, the superstition is often viewed as unsubstantiated. Backtests reveal that Friday the 13th has historically performed better than an average Friday. The average gain in the stock market on Friday the 13th has been higher than typical trading days.

What is the average gain in the stock market on Friday the 13th?

There have been 107 trades recorded for Friday the 13th since 1960, contributing to the backtested performance analysis. The average gain in the stock market on Friday the 13th has been 0.13%, which is significantly higher than the average gain on a random day of the week (0.03%).

Similar Posts