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 Gigamon (NYSE:GIMO) closed Friday up about 26% following the release of the company's first-quarter earnings after Thursday's closing bell.

So what: Gigamon reported $46.9 million in revenue and adjusted earnings of $0.13 per share for the quarter. Both results far exceeded Gigamon's year-ago quarterly results, which produced $31.8 million in revenue and a loss of $0.07 per share. Wall Street's analysts had expected the company to post earnings of just $0.04 per share on $42.2 million in revenue. Gigamon issued second-quarter guidance during its earnings call that anticipates revenue in the range of $48 million to $51 million, with adjusted earnings ranging from $0.11 to $0.15 per share. Both ranges come in above Wall Street's consensus targets of $49.3 million in revenue and $0.11 in EPS.

Now what: Today's pop caps off a stunning six-month gain of 120% that followed the stock's crushing 32% loss last summer following underwhelming guidance, and it looks like the company may have learned from that mistake. Its second-quarter revenue range is 42% higher than the year-ago quarter at its midpoint, but only 6% above the first-quarter's strong results. The company's EPS guidance is also a marked improvement over 2014's second-quarter adjusted loss of $0.04 per share, but is merely the same as the first quarter's result at its midpoint.

The company is hardly cheap -- it continues to report steep GAAP losses and Wall Street's full-year consensus for $0.40 in adjusted EPS translates to a heady adjusted forward P/E of 73.8. Investors don't seem to care so long as Gigamon keeps posting big growth, but nearly every high-flying stock eventually has to face financial reality. Can Gigamon put together another six-month double? It's unlikely, but investors will need to weigh the possibility of a slowdown against the optimism currently baked into share prices before considering yesterday's report a buy sign.