Sept 30 is the worst day for the stock market - Bespoke

According to data compiled by analysts from Bespoke, today will be one of the worst days for the stock market - if history is any guide.

As Bespoke notes, while March 30th has traditionally been the day where the S&P 500 has been up the least, 9/30 is tied for fifth at 38%.

Since 1945, the S&P 500 has dipped an average of 0.15% (median: -0.25%) with positive returns just 38% of the time on 9/30.  While the long-term performance of the S&P 500 on the last day of September has been soft, in recent years it has been even worse.

In the current bull market, it has traded lower if the stock market has been open on 9/30. At least there’s only one day left in September after today!

According to FactSet, weekly performance in 2015 for the S&P 500 was among the worst in September.

Worst days of the year

Financial blogger Ryan Detrick was among those who noted the same tendency. He signaled that the 38th, 39th and the 40th weeks of the calendar - which fall in September - tend to be the weakest of the year dating back to 1950.

September has marked a particularly rough stretch for the S&P 500 with only the week of Sept. 11 closing higher as China’s economic downturn, global swings, and lack of clarity on the timing of the Federal Reserve’s expected interest-rate hike have shaken investor confidence.

Many strategists, however, see a great buying opportunity right now. As Callum Thomas, investment strategist at AMP Capital, advises, sell in May, come back in October!