Despite a mixed session for the major market indexes, shares of Ciena Corporation (CIEN - 13.62) are broadly higher today. Late Monday, word hit the Street -- via a regulatory filing -- that Soros Fund Management disclosed a 4.99% passive stake in CIEN as of Aug. 31. Soros Fund Management is the hedge fund helmed by well-known investor George Soros. In today's trading, CIEN is up roughly 6%.

However, the stock's path higher isn't exactly clear. CIEN's rally today has propelled the stock squarely into resistance at its 10-week moving average, which hasn't been surmounted on a weekly closing basis since late May. In the intervening months, this troublesome trendline has ushered CIEN to a year-to-date deficit of 39%.

Appropriately enough, there are quite a few bears betting on CIEN's technical woes to continue. Short interest on the tech stock rose by approximately 20% during the most recent reporting period, and now accounts for 28.8% of the equity's float. At CIEN's average daily trading volume, it would take more than four days for all of these shorted shares to be repurchased.

In fact, it's quite likely that shorts are driving today's spike in CIEN shares. If some of the weaker bearish hands were rattled by news of the Soros stake, a rush to cover could be prompting the outsized rally.

However, from a broader perspective, it's too soon to turn bullish on CIEN. The stock's longer-term downtrend appears to be firmly intact, despite today's pop. Plus, there's still room for sentiment to grow more bearish on the shares, hinting at additional selling pressure that could soon be unleashed.

Specifically, Zacks reports 13 "buy" or better ratings from brokerage firms, compared to eight "holds" and one "sell." As CIEN's lackluster price action persists, a round of downgrades from this group could send the stock reeling.