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.


Feb. 10

Weekly Loss

My Watchlist

Diamond Foods (Nasdaq: DMND) $23.52 (38%) Add
iRobot (Nasdaq: IRBT) $25.27 (32%) Add
Astex Pharmaceuticals (Nasdaq: ASTX) $2.04 (27%) Add (Nasdaq: SOHU) $50.93 (19%) Add
Amtech Systems (Nasdaq: ASYS) $9.28 (17%) Add

Source: Barron's.

Diamond in the rough? You better believe it. The nutty company is booting its CEO and CFO, restating past financials, and is likely not going to close on its deal to acquire Pringles.

iRobot pulled the whole "I'm sorry Dave, I'm afraid I can't do that" routine on investors after delivering uninspiring guidance for 2012. The company makes military automatons as well as consumer robotics.

Astex Pharmaceuticals called in sick after an advisory panel -- not the FDA -- voted against recommending the biotech's treatment for acute myeloid leukemia for patients over the age of 65. Fellow Fool Sean Williams sees the drop as a buying opportunity given Astex's meaty cash position and diversified revenue stream.

Chinese dot-com Sohu slipped after warning that earnings for its current quarter would come in at less than half of the $1.15 a share that analysts were projecting.

Solar stocks may have bounced back last week, but Amtech Systems missed the wake-up call. The solar equipment supplier saw its shares slide after posting a quarterly loss and warning of a widening deficit for the current quarter.

It was a rough week for these five stocks. If you want to shake yesterday's losers and ride tomorrow's winners, a new special report reveals The Motley Fool's top stock for 2012. It's free, but only for a limited time, so check it out now.