Ending an up-and-down week on the rise, the S&P 500 Index (SNPINDEX:^GSPC) seized on Friday's Labor Department figures, which showed positive trends in hiring, as the U.S. economy added 175,000 jobs in May. Surging for a second straight day with 20-point, or 1.3%, gains, the index closed at 1,643. Despite the bullish direction of the macroeconomy, these three S&P components weren't even close to ekeing out gains, as investors cringed at recent developments that threaten returns. 

Far and away the biggest disappointment in the index today was Iron Mountain (NYSE:IRM), as shares in the business information management company slumped 15.8%. The culprit behind the mass sell-off was actually the Internal Revenue Service, which took a hard line with the company on its request to be taxed as a REIT. REITs, or Real Estate Investment Trusts, enjoy certain tax advantages that other corporate structures don't allow. Unfortunately for Iron Mountain shareholders, the IRS has formed an internal "working group" to examine its current requirements for companies seeking REIT status.

The second of today's laggards, Cliffs Natural Resources (NYSE:CLF), fell 3.3%. The stock had quite a volatile week, with three days of price swings of 3% or more. Cliffs, which is heavily involved in the iron ore and coal markets, has experienced a mass shareholder exodus in 2013, as shares have cratered more than 50%. With stagnant iron ore prices, and coal's stigma as a "dirty" source of energy, it's not hard to see the obstacles facing the company. 

Finally, Thermo Fisher Scientific (NYSE:TMO), which makes analytical equipment in the health-care sector, lost 2.7% Friday. Though investors can be relieved that today's decline has nothing to do with the IRS, they were understandably not impressed with the company's decision to raise about $2.2 billion through what amounts to the future issuance of more stock. Thermo Fisher will officially issue additional shares when the deal to buy Life Technologies (for $13.6 billion) closes, which is expected to be early 2014. The funds from the offering will be put toward the acquisition.

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