Plus, during the past 10 days, NOK has racked up a call/put ratio of 3.98 on the ISE. In other words, traders have bought nearly four times more bullish bets than bearish in the past few weeks. This ratio ranks higher than 82% of other such readings in the past year, indicating near-extreme levels of optimism among traders on this exchange.

The most popular call in the October series is the 21 strike, with open interest of 32,278 contracts. NOK has already been stymied by resistance in this region, and the heavy accumulation of call open interest here could exacerbate the stock's difficulties at this level. Even more troubling, the equity's 20-day moving average is dropping through the 21 neighborhood, further augmenting this region's potency as potential resistance.

Unfortunately, Nokia is vulnerable to more bearish hits from analysts. Zacks reports that 11 out of 18 brokerage firms maintain a "buy" or better rating, leaving ample opportunity for downgrades. Plus, Thomson Financial pegs the average 12-month price target on NOK at $33.22 -- a hefty 64% premium to the stock's closing price on Thursday. In light of today's developments, more downward revisions to this consensus estimate could be in the offing.

Overall, the overwhelming amount of optimism being thrown at this stock isn't justified by its technical or fundamental performance. If this bullish sentiment unwinds, the resulting selling pressure could exacerbate NOK's losses. In the meantime, keep an eye on the 20 level. The shares haven't finished a week south of this round-number region since July 2006, and a close today below this area could indicate that an all-out sell-off is in store.

Elizabeth Harrow is an analyst and financial writer in the research department at Schaeffer's Investment Research. She is featured in the video series Schaeffer's Daily Q&A on SchaeffersResearch.com.