The iShares Nasdaq Biotechnology ETF (IBB) fell 6.2% on the week although the biotech exchange-traded fund rose 2.3% today.
Cramer said during CNBC's "Stop Trading" segment today's boost is thanks to two of his "four horsemen" -- Celgene (CELG), up 2%, and Gilead Sciences (GILD), up nearly 5%. Both companies reported "inspiring" earnings results, Cramer said.
Cramer said two other biotechs look ready to re-test previous stock highs: BioMarin Pharmaceutical (BMRN), which he said has the best orphan drug pipeline and an "excellent" product portfolio, and Receptos (RCPT).
"Those are the two that I like very much," he said, adding that "biotech is not done" going higher.