Coming in first in terms of stock performance was Atara Biotherapeutics, up 52 percent since the start of 2018. Most of its move came after the J.P. Morgan conference.
The cause? Atara, a small company that develops immunotherapy treatments for cancer and multiple sclerosis, announced that the FDA approved one of its multiple sclerosis drugs for a Phase 1 study.
Better yet, Atara has a treatment for the Epstein-Barr virus (which causes mononucleosis, or mono) in Phase 3 trials — one step away from an FDA review.
"Put it all together, though, and it feels like the investors are warming to speculative biotechs again, even with the tape showing signs of raggedness today," Cramer said on Tuesday.
Up 47 percent for the year, Alder Biopharmaceuticals was the conference's second-biggest winner. Another small, development-stage biotechnology player, Alder announced strong clinical trial outcomes for its top medication, a migraine prevention drug.
"I like the story that CEO Randall Schatzman told us last week," Cramer said. "But remember, Alder's still a very early-stage company and there are plenty of pitfalls remaining before FDA approval, including, by the way, the fact that some competitors are ahead of them in the process."
Other notable winners include Coherus Biosciences, a generic drugmaker with a 43 percent gain, and Illumina, a DNA-sequencing play up over 10 percent after the company introduced a new, low-cost sequencing machine.
(Cramer did caution investors about Coherus, which he saw as a commodity business with no patent protection.)