That is the kind of story that has defined the most famous initial public offerings of Silicon Valley, but it never materialized for Facebook, perhaps the most well-known tech IPO of all.

FORBES: Facebook's IPO Pop Is Finally Here Five Months Later

But in this case the bump never materialized, so it's back on the list.

FORBES: Magazine Article

Byetta is a twice-a-day shot, a big disadvantage, but it actually helps patients lose a few pounds, a hoped-for advantage that never materialized for the Merck and Novartis drugs.

FORBES: Magazine Article

In December of 2001, Merck seemed to indicate it would mount such a study--but the clinical trial never seems to have materialized, even though the firm started a similar trial for Arcoxia, a successor drug to Vioxx.

FORBES: Merck's Missing Vioxx Study

In 2001, the company said it would to conduct a big study testing Vioxx's heart safety, but the clinical trial never materialized.

FORBES: Merck Withdraws Vioxx