Looking at a stock chart today, you'd think Riverbed Technology (Nasdaq: RVBD) had filed for bankruptcy or at the very least completely missed earnings estimates. Few events are capable of giving a 23% overnight haircut to a stock.

Neither nightmare scenario has happened, though. Instead, the network efficiency specialist reported $0.21 of adjusted earnings per share -- in line with analyst targets -- on sales of $170 million, about $2.5 million short of estimates. That's a 1.5% revenue miss for those keeping score at home, or 35% year-over-year growth that also produced 81% higher earnings. That's not normally grounds for 10 lashes in a public square.

Then again, Riverbed shares had gained a heart-stopping 177% in the 12 months prior to this report and are trading at triple-digit P/E ratios. Simply put, the company had to absolutely crush estimates this quarter in order to deserve the very rich valuation investors have bestowed upon it, and that just didn't happen.

The lack of impressive numbers from this highflier also dragged down sector rivals: F5 Networks (Nasdaq: FFIV) dropped as much as 7% on the eve of its own quarterly report (and sports a trailing P/E ratio of 46), and Acme Packet (Nasdaq: APKT) -- trading for 93 times trailing earnings today -- took an 8% hit. Even oblique competitors and sector compatriots such as Finisar (Nasdaq: FNSR) and JDS Uniphase (Nasdaq: JDSU) are lagging the market significantly today despite a lack of company-specific news.

Wall Street analysts tend to tag this drop as a buy-in opportunity on Riverbed. All-Star CAPS analyst FBR Capital Markets, for example, attributes the slight miss to "macro headwinds in the EMEA region" and expects nothing worse than a few deals slipping into the next quarter. I'd agree, particularly since a stumbling, bumbling Cisco Systems (Nasdaq: CSCO) is leaving plenty of room for up-and-comers like Riverbed to steal pieces of its traditional business strongholds.

At the end of the day, Riverbed remains a tremendously expensive stock albeit less so than it was yesterday. In short, this is a consummate Rule Breaker. A lot of things have to go right in order to justify these prices, but I wouldn't be surprised at all to see it happen. Short of signing up for a free Rule Breakers trial, the best way to keep track of Riverbed's ups and downs is to add the stock to your Foolish watchlist. It's a great way to stay on top of news and analysis of your favorite stocks; just click here to get started right away.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. The Fool owns shares of and has created a bull call spread position on Cisco Systems. Motley Fool newsletter services have recommended buying shares of Acme Packet, Cisco Systems, and Riverbed Technology, as well as shorting JDS Uniphase. 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. You can check out Anders' holdings and a concise bio, follow him on Twitter or Google+, or peruse our Foolish disclosure policy.