Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Radware (NASDAQ:RDWR) have fallen by as much as 24% after the company announced disappointing preliminary earnings for the first quarter.

So what: Revenue is expected to be $45 million, which is well below Radware's previous guidance of $48.5 million to $49.5 million. Analysts were expecting the company to report $49.2 million. Non-GAAP earnings per share should be approximately $0.30, leaving a lot to be desired compared to guidance of $0.40 to $0.43 per share in adjusted profits. The Street was modeling for $0.43 per share.

Now what: CEO Roy Zisapel said that sales in the U.S. market were strong, but weak performance in the Europe, Middle East, Africa, and China geographical segments dragged down overall results. Needham analyst Alex Henderson told Bloomberg that existing customers are taking longer to order for projects. Networking peer F5 Networks also posted preliminary earnings yesterday that were worse than expected, showing that the broader sector is facing headwinds.

Interested in more info on Radware? Add it to your watchlist by clicking here.

Fool contributor Evan Niu, CFA, has no position in any stocks mentioned. The Motley Fool recommends F5 Networks. The Motley Fool owns shares of F5 Networks. 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.