There's never a shortage of losers in the stock market. Let's take a closer look at five of this past week's biggest sinkers.

Company

Jan. 25

Weekly Loss

My Watchlist

IAMGOLD (NYSE:IAG)

$8.39

24%

Add

Neutral Tandem (NASDAQ:IQNT)

$2.70

13%

Add

Apple (NASDAQ:AAPL)

$439.88

12%

Add

Arena Pharmaceuticals (NASDAQ:ARNA)

$8.71

11%

Add

Coeur d'Alene Mines (NYSE:CDE)

$21.92

11%

Add

Source: Barron's.

Investors rotated out of gold mining stocks last week. Several miners suffered double-digit dips, but IAMGOLD led the way lower with its 24% drop.

The gold and niobium miner didn't do itself any favors by sticking to its production guidance for 2013 but warning of a healthy spike in production costs.

Neutral Tandem was a victim of a reshuffling of the S&P Dow Jones Indices' lineups, as the stock was booted from the S&P SmallCap 600 after its low market cap -- now below $100 million -- made it no longer representative of the small-cap realm.

Apple's nightmare continues. The consumer tech giant stumbled after posting disappointing quarterly results. Apple was excited to sell more than 75 million iOS devices, but they're not as profitable as they used to be. Gross and net margins were squeezed, and that may not get better in the near future as Apple has to sacrifice margins to maintain market share.

Arena Pharmaceuticals shed some weight after European regulators asked for more information on its obesity drug. This isn't necessarily a deal-breaker, though it doesn't bode well for Belviq's chances for approval in Europe.

Coeur d'Alene Mines stumbled after kicking off the week with a BMO Capital Markets downgrade. It then went on to take on more debt by offering $200 million in senior notes.

Longtime Fool contributor Rick Aristotle Munarriz has no position in any stocks mentioned. The Motley Fool recommends and owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.