So far this year, companies with shares coming off of IPO lock-ups have had about a 50-50 chance of having their stock prices fall as a result. The odds held up last week as InterMune (ITMN) added $0.125 to $41.375 on 277,500 shares on Tuesday when the lock-up expired on 8.4 million shares. The pulmonary, infectious and congenital diseases company soared over the remainder of the week to close Friday at $55.375, up $13.625 (33 percent).

On the other side of the ledger, microfluidics play Aclara (ACLA) lost $6.50 (18 percent) to $30.50 on 1.5 million shares on Monday after 9 million shares came off lock-up over the prior weekend. It didn't help that the NASDAQ Composite slid 3 percent on Monday. ACLA, which has divided its lock-up into three dates, closed Friday at $27.875, down $9.125 (25 percent). The final 9 million shares will be released on Nov. 1.

Both IPOs floated in March. ACLA raised $217.4 million through the sale of 10.4 million shares at $21. ITMN raised $125 million by selling 6.25 million shares at $20.

Another 16 IPOs will come off lock-up this year (see "Upcoming Lock-ups"). While most of the stocks are off sharply from their highs, there are still profits to be had. All but one - cancer play Allos (ALTH) - are trading above their IPO price. And most of the shares that are covered under lock-ups were purchased in private rounds at significantly less than the IPO price.

Three companies with shares coming off lock-up this past weekend and this week showed mixed performance last week. Infectious disease play IntraBiotics (IBPI) was up $0.50 to $16.625, while ALTH dipped $0.438 to $11.063 and biological test supplier Luminex (LMNX) dropped $2.625 to $28.

Genmab: Prettying up the bride

Genmab and parent Medarex (MEDX) have quietly taken a number of recent steps that appear to be designed to divide up worldwide responsibilities in their antibody space and groom the Copenhagen company for an IPO in October.