In this series, we take a look at the 25 stocks on the S&P 500 Index (SPX) that have turned in the worst performance during the past decade -- what went wrong, and what happens next.

Among telecom stocks that got smacked during the past decade, Ciena Corporation (NASDAQ: CIEN) took the hardest hit -- at least, among those companies that still exist in the same incarnation. Yes, that comment was directed at you, Alcatel-Lucent (NYSE: ALU).

Other telecom losers on our roster include Qwest Communications (NYSE: Q), JDS Uniphase (NASDAQ: JDSU), and Tellabs, Inc. (NASDAQ: TLAB) -- the latter of which also plays a key role in the forthcoming Ciena saga.

What went wrong? At number 3 on our list of SPX laggards, CIEN lost 90% of its value in the decade that ended June 30, 2008. The stock peaked at a split-adjusted $1,057 in October 2000, a zenith that marked the top of a steep ascent. The equity's ensuing plunge would be just as dramatic.

In this series, we take a look at the 25 stocks on the S&P 500 Index (SPX) that have turned in the worst performance during the past decade -- what went wrong, and what happens next.

Add Tellabs, Inc. (NASDAQ: TLAB) to the list of casualties from the Great Telecom Bust of the new millennium. It was a bloody massacre that highlighted the difficulties of forecasting; and, in particular, the danger of forecasting through the distorted lens of the dot-com bubble. When Internet traffic stopped multiplying at its previously exponential rate, the market was faced with a glut of supply and waning demand. Only the strong survived, but even they couldn't manage to thrive.

What went wrong? At No. 5 on our list of SPX underperformers, TLAB lost 87% of its value during the decade that ended June 30, 2008. The stock peaked at $77.25 in November 1999 before its momentum shifted.

In 1999, Tellabs was on an acquisition binge. A planned buyout of Ciena Corporation (NASDAQ: CIEN) had hit the skids, and the company made up for the loss by absorbing a series of smaller players -- within months, Tellabs told investors it would buy Alcatel's DSC Communications unit, Netcore Systems, and Salix Technologies.

MOST NOTEWORTHY: Nike Inc (NYSE: NKE), Foot Locker Inc (NYSE: FL), Tellabs Inc (NASDAQ: TLAB), ADTRAN, Inc (NASDAQ: ADTN) and Bookham, Inc (NASDAQ: BKHM) were today's noteworthy downgrades:

• Banc of America downgraded shares of both Nike and Foot Locker to Neutral from Buy, as the firm believes industry pressures in the U.S. could more than offset the potential turn in Europe and benefit from the 2008 Olympics.
• Cowen downgraded shares of ADTRAN, Bookham and Tellabs to Neutral from Outperform.
• Goldman Sachs also downgraded shares of Tellabs, to Sell from Neutral, as the firm believes the stock fully discounts the expected sales and margin improvement.

OTHER DOWNGRADES:

• Allergan Inc (NYSE: AGN) was downgraded to Equal Weight from Overweight at Morgan Stanley citing limited upside.
• Friedman Billings removed The Cheesecake Factory Incorporated (NASDAQ: CAKE) from its Top Picks and maintained its Outperform rating.
• Lehman downgraded shares of The First American Corporation (NYSE: FAF) to Equal-Weight from Overweight on increasing risk to the company's title margin and regulatory concerns.
• Matrix USA downgraded shares of Lowe's Companies Inc (NYSE: LOW) to Buy from Strong Buy on valuation.

Whether it's building a distribution system that lets your cable company transmit voice-video-data, or providing the systems that enable your phone company to build its fiber optic backbone network, there is an outfit in Naperville, Illinois that has the breadth of experience to make the process a smooth one.

Tellabs Inc. (NASDAQ: TLAB) designs, develops and deploys telecommunications networking products. Its portfolio includes systems for wireline and wireless transport, access networking, broadband data, optical transport, and voice-quality enhancement. Clients include cable operators, corporations, government agencies and such carriers as Verizon Communications (NYSE: VZ), AT&T (NYSE: T) and Sprint Nextel (NYSE: S). Alcatel-Lucent (NYSE: ALU), Cisco Systems (NASDAQ: CSCO) and Nortel Networks (NYSE: NT) are major competitors.

The company pleased investors last week, when it reported Q1 EPS of six cents and revenues of $452 million. Analysts, who said the company saw strong demand for its advanced phone switching gear, had been expecting five cents and $452 million. Management also guided Q2 revenues to $500-$520 million, versus Street consensus of $502.5 million. The CEO said the firm was encouraged that its new technologies are "taking root" in service provider networks. TLAB shares popped into a bullish "flag" consolidation pattern on the news. Prices frequently exit flags moving in the same direction they were traveling when they entered them. For TLAB, that break out commenced today.

Brokers recommend the issue with three "strong buys," three "buys," 12 "holds" and five "sells." Analysts see a 42% growth rate, through the next year. The TLAB Price to Sales ratio (2.39), Price to Book ratio (1.60), Price to Cash Flow ratio (15.90) and Price to Free Cash Flow ratio (17.46) compare favorably with industry, sector and S&P 500 averages.

Institutional investors hold about 70% of the outstanding shares. The stock is one of those used to calculate the S&P 500 Index and the Nasdaq 100 Index. Over the past 52 weeks, it has traded between $8.84 and $16.40. A stop-loss of $9.55 looks good here.

Larry Schutts is a contributing editor for Theflyonthewall.com and the Vice-President of Stockwinners.com.

MOST NOTEWORTHY: Lear Corp (LEA) and Tellabs Inc (TLAB) were today's most notable upgrades:

• Lear Corp (NYSE: LEA) was upgraded to Neutral from Underperform at Credit Suisse following the $2.31B cash bid from Carl Icahn.

• Merrill Lynch upgraded Tellabs Inc (NASDAQ: TLAB) to Buy from Neutral, citing expectations for an improvement in cross-connect demand and margins; the firm expects Tellabs to benefit from AT&T's (NYSE: T) new broadband initiatives, a demand recovery at Cingular, T-Mobile 3G deployment plans and an increase in Sprint/Nextel (NYSE: S) base stations.

OTHER UPGRADES:

• JP Morgan upgraded Nvidia Corp (NASDAQ: NVDA) to Overweight from Neutral based on expectations for gross margin upside to be driven by improved unit costs and market share gains in the notebook segment.

• Raymond James upgraded shares of AirTran Holdings Inc (NYSE: AAI) to Outperform from Market Perform with a $14 target.

• CIBC upgraded Kronos Inc (NASDAQ: KRON) to Sector Outperformer from Sector Perform, with a $46 target, as they find valuation attractive at current levels given their increasing confidence operations are improving.

• State Street Corp (NYSE: STT) was upgraded to Equal Weight from Underweight at Morgan Stanley following the news of the Investors Financial Services Corp (NASDAQ: IFIN) acquisition.

• Triad Hospitals Inc (NYSE: TRI) was upgraded to Neutral from Sell at Bank of America.

• Overstock.com Inc (NASDAQ: OSTK) was upgraded to Neural from Sell at First Albany, as the worst is already reflected in the stock's valuation.

• Matrix USA upgraded Estee Lauder Co Inc (NYSE: EL) to Hold from Sell based on fundamental trends.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).

MOST NOTEWORTHY: Wal-Mart (WMT) and Motorola (MOT) were the most notable downgrades this morning.

• Goldman Sachs downgraded Wal-Mart Stores Inc. (NYSE: WMT) to Neutral from Buy; citing weaker sales and expected heavy markdowns.

• Credit Suisse removed shares of Motorola Inc. (NYSE: MOT) from their Focus List.

OTHER DOWNGRADES:

• Bear Stearns downgraded the Restaurant Sector to Market Weight from Overweight, citing valuations and softening fundamentals. In addition, Applebee's International Inc. (NASDAQ: APPB) and P.F. Chang's China Bistro Inc. (NASDAQ: PFCB) were both downgraded to Underperform from Peer Perform.

• Following the lower-than-expected Q4 guidance, Morgan Keegan downgraded shares of Tellabs Inc. (NASDAQ: TLAB) to Market Perform from Outperform, as they do not expect a quick earnings recovery.

• Ensco International Inc. (NYSE: ESV) was downgraded to Underweight from Equal Weight at JP Morgan; the firm says there is growth risk to the global jackup market including overcapacity in early 2008.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).