The Dow Jones Industrials (DJINDICES:^DJI) fell 24 points, or just over 0.1%, on Monday to close at 17,623. Three stocks accounted for the lion's share of the downward pressure on the Dow, with Apple (NASDAQ:AAPL) leading all 30 Dow stocks downward in terms of percentage declines. Energy stocks Chevron (NYSE:CVX) and ExxonMobil (NYSE:XOM) were also substantial losers on the day, falling more than 2% each.

In the following slideshow, you'll find a short explanation of what happened to the Dow and these three stocks. Although a single day's movements aren't always important to your long-term investing strategy, it still makes sense to track what's happening with the stocks in your portfolio to make sure that you don't get blindsided by unexpected bad news -- especially during turbulent periods like peak earnings season.

Dan Caplinger owns shares of Apple. The Motley Fool owns shares of and recommends Apple. The Motley Fool owns shares of ExxonMobil. The Motley Fool recommends Chevron. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.