What Is The Weakest Month In The Stock Market?

Last Updated on November 22, 2022

Seasonal trends in the financial markets are many, and the stock market is no exception. Some months are better than others. What is the weakest month in the stock market?

The weakest month in the stock market is September. The second weakest month is June.

To find the weakest month, we backtested the S&P 500 back to 1960. The results are found in the table further below in the article:

What is the weakest month in the stock market?

We ranked the performance of all months since 1960. This is how we did it:

We buy at the close of the last month and we sell at the close of the current month.

The results for all months look like this:

The first column shows the result for each month.

Clearly, September is the weakest month in the stock market with an average negative return of 0.74%. June is the second weakest month – also negative with 0.15%.

Code for the weakest month in the stock market

We used Amibroker for our backtest. This is an easy program to learn and you can backtest individual stocks or a portfolio of stocks. If you find something that works and would like to trade live, you can easily use the same code for automated trading with a few modifications. Please read our Amibroker review.

We have also made an inexpensive product that has summarized the code of all the profitable trading strategies (the ones which are free) we have made since our start in 2012. All the code also come in plain English in case you want to develop a Python trading strategy backtest. You can order on the banner below:

Seasonal trading strategies

Are you interested in a seasonal trading strategy – both in the stock market or in other markets? We have made many. Some are free seasonal trading strategies, but we save our best strategies for our paying subscribers: