The stock market didn't move much last week, but there are always losers to be found.

Let's take a closer look at five of this past week's biggest sinkers.

Company

May 13

Weekly Loss

My Watchlist

BioMimetic Therapeutics (Nasdaq: BMTI)

$8.11

(39%)

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Penson Worldwide (Nasdaq: PNSN)

$3.34

(38%)

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Ener1 (Nasdaq: HEV)

$1.51

(36%)

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SmartHeat (Nasdaq: HEAT)

$2.15

(28%)

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STEC (Nasdaq: STEC)

$14.80

(27%)

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Source: Barron's.

BioMimetic Therapeutics received an unconvincing panel vote for its Augment bone graft treatment. The FDA advisory committee's vote -- while narrowly positive -- still leaves some doubt as to Augment's potential approval.

Penson got smacked around when the independent clearing broker revealed $43 million in non-accruing bonds tied to a horse track headed up by one of its directors. Investors don't like whiffs of controversy, even though the director in question resigned from the board on Thursday.

Ener1 was downgraded by Wunderlich Securities after posting a sharp quarterly loss. Ener1 had to write off its investment in a major automotive customer, leaving Wunderlich to question the viability of the cash-strapped electric car battery specialist.

SmartHeat felt the heat after serving up lackluster financials. The Chinese clean-tech posted a loss of $0.10 a share on a 16% top-line dip. Analysts figured that the alternative energy specialist would post a small profit.

STEC hit the deck after the solid-state drive manufacturer cranked out a ho-hum quarter and hosed down its near-term guidance.

It was a rough week for these five stocks. Let's see which ones bounce back this week.

Which of these five stocks do you think bottomed out last week? Share your thoughts in the comment box below.