October has proven to be an eventful month for the stock market. Investors have been keeping a close eye on various factors, such as the war in the Middle East, company earnings, and Treasury debt yields. Additionally, the Federal Reserve's actions in response to high inflation have been a significant focus. Let's take a closer look at the best and worst performers in the Dow Jones Industrial Average, Nasdaq 100, and S&P 500 during October.

Dow Jones Industrial Average

Top Performers

The standout stock in the Dow was Verizon Communications (ticker: VZ), which saw an impressive gain of 8.4%. The company's third-quarter results played a significant role in driving up its stock value. Following closely behind was Nike (NKE) with a solid 7.5% rise.

Microsoft (MSFT) secured the third spot with a substantial jump of 7.1%. The company's strong financial results, announced on Oct. 24, provided an extra boost. Notably, the Azure cloud business exceeded growth expectations set by management.

Bottom Performers

Unfortunately, Caterpillar (CAT) experienced a rough month and emerged as the biggest loser in the Dow. A poor earnings report contributed to a significant drop, resulting in a disappointing 17% decline for October.

Coming in second as the worst performer was Chevron (CVX), which recorded a loss of 13%. This drop can be attributed to weaker-than-expected third-quarter earnings announced last week. Furthermore, news earlier in the month about Chevron's acquisition of independent oil and gas company Hess (HES) in an all-stock transaction weighed down the stock.

The stock market has certainly experienced ups and downs in October, highlighting both winners and losers across various sectors. As we move into November, investors will continue to monitor these developments to make informed decisions.

Nasdaq 100

Netflix (NFLX) Shines in Nasdaq 100

Align Technology Struggles in Nasdaq 100

Unfortunately, Align Technology had a less favorable month in the Nasdaq 100. The company reported disappointing earnings and revenue for the third quarter. In response to weakening demand, management revised their financial forecasts for fiscal 2023. Consequently, shares of Align Technology fell by 40% in October, making it the worst-performing stock in the index for the month. This decline represents the company's worst month since October 2018.

S&P 500

Allstate Leads in S&P 500

October witnessed Allstate (ALL) as the standout performer in the S&P 500. The stock experienced a remarkable 15% gain, marking its best month since November 2020.

SolarEdge Technologies Struggles in S&P 500

Conversely, SolarEdge Technologies (SEDG) faced significant challenges in the S&P 500. The stock fell victim to a downturn that has also affected its competitors. The Invesco Solar ETF, which includes SolarEdge Technologies, experienced a substantial drop of 43% in 2023, making it the ETF's worst year since 2016. This decline can be attributed to rising interest rates and regulatory changes in California, which have discouraged households from installing solar panels.

SolarEdge Technologies released preliminary financial data for the third quarter on Oct. 19, revealing lower-than-expected results. Chief Executive Zvi Lando attributed this to significant cancellations and delays from European distributors. As a result, the stock plummeted by 73% this year, with a loss of 41% in October alone, marking its worst month on record.