---
title: "Has the US stock market entered the traditional September off-season?"
type: "News"
locale: "en"
url: "https://longbridge.com/en/news/255534578.md"
description: "Bank of America: Since 1927, in the first year of the U.S. presidential election cycle, the probability of the S&P 500 index declining in September has reached 58%, making it the second worst-performing month in history. During this period, the average return of the index was -1.62%. October also performed weakly, with an average return of -0.58%. Overall, since 1950, September has been the month with the worst average returns. In the 18 election years since 1950, there have only been 3 years in which September saw an increase. Historical data suggests that market volatility is imminent"
datetime: "2025-09-02T02:40:37.000Z"
locales:
  - [zh-CN](https://longbridge.com/zh-CN/news/255534578.md)
  - [en](https://longbridge.com/en/news/255534578.md)
  - [zh-HK](https://longbridge.com/zh-HK/news/255534578.md)
---

> Supported Languages: [简体中文](https://longbridge.com/zh-CN/news/255534578.md) | [繁體中文](https://longbridge.com/zh-HK/news/255534578.md)


# Has the US stock market entered the traditional September off-season?

Bank of America: Since 1927, in the first year of the U.S. presidential election cycle, the probability of the S&P 500 index declining in September has reached 58%, **making it the second worst-performing month in history.**

**During this period, the average return of the index was -1.62%. October also performed weakly, with an average return of -0.58%.** Overall, since 1950, September has been the month with the worst average returns.

In the 18 post-election years from 1950 to present, there have only been 3 years where September saw an increase. Historical data suggests that market volatility is imminent.

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