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 computer peripherals company Logitech International SA (LOGI -0.99%) surged 15% today after its quarterly results and guidance impressed Wall Street.

So what: Logitech shares have slumped in recent months on worries over slumping demand, but a wide Q1 beat -- EPS of $0.13 on revenue of $483.2 million vs. the consensus of just $0.04 and $476.9 million -- coupled with upbeat guidance is quickly easing those concerns. While Logitech's top line inched up just 1%, sales in its growth category -- which includes PC gaming, tablet accessories, and mobile speakers -- increased a solid 17%, reigniting plenty of optimism among analysts over the company's long-term turnaround potential.

Now what: Management now sees full-year 2015 operating income of $170 million, well above its prior view of $145 million, on sales of $2.16 billion. "As planned, our cost reduction actions continue to drive increased operating leverage," said President and CEO Bracken Darrell. "As we proceed through Fiscal Year 2015, we will continue to focus both on accelerating sales growth and on achieving our improved outlook for profitability." More importantly, with Logitech continuing to boast a rock-solid balance sheet and reasonable forward P/E in the mid-teens, the downside still seems limited enough to bet on that bullishness.