Mark Duvall

Organovo recently soared to the $1 billion level for the first time in its history. But management has been quick to sell stock and file a new equity registration statement. Investors may want to think about selling at these peak prices.

Organovo's 3-D bioprinting technology holds the potential to revolutionize medicine in coming decades. But after quadrupling in the past year, the stock seems to have gotten ahead of any realizable revenue prospects.