The 5-Day Low Overnight Trading Strategy (S&P 500 Overnight)

Last Updated on August 26, 2021 by Oddmund Groette

The S&P 500 has shown strong mean reversion tendencies for many decades. One reason for this is the tailwind in the form of 0.04% average return from the close until the next day open.

This article looks at the performance of the overnight session when the S&P 500 opens at a 5-day low but at the same time, the close is higher than the open.

Let’s turn this into a testable trading strategy:

The 5-day low overnight trading strategy

Here is the testable trading strategy in plain English:

  1. SPY must open at a 5 day low.
  2. The close must be higher than the open.
  3. If 1 and 2 are true, then enter on the close.
  4. Exit tomorrow’s open.

I have previously written about a 5-day low strategy in SPY.

Here are the stats:

P/L in % #Fills Avg.
15.93 61 0.26

Test period from 2005 until July 2013. Here is the profit curve:

The biggest winner is 6% (in October 2008). Excluding that one still gives an average of 0.17%.


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Disclosure: We are not financial advisors. Please do your own due diligence and investment research or consult a financial professional. All articles are our opinions – they are not suggestions to buy or sell any securities.