Investors should be wary of biotech stocks moving forward, even as some big names continued their tear on Friday, said CNBC "Fast Money" trader Tim Seymour.

"You have to be cautious," Seymour said.

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Celgene closed just below a 52-week high on Friday, while Biogen surged nearly 10 percent. The iShares Nasdaq Biotechnology ETF closed in positive territory, up more than 20 percent this year.

Seymour warned that the fund sat in "overbought territory," saying that it might soon pull back. Trader Brian Kelly agreed, adding that investors might want to take profits on biotech names next week.

Some biotech names may not have exhausted their momentum, trader Guy Adami said. He believes that Celgene could move even higher, adding that Gilead and Amgen may have room to run.

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Gilead and Amgen both rose more than half a percent on Friday, closing around $102 and $170 per share, respectively.

Trader Steve Grasso said he holds a long position in Clovis, which closed nearly 4 percent lower, around $78 per share, on Friday.

Disclosures:

Tim Seymour

Tim Seymour is long T, BAC, C, DIS, XOM, F, GE, GM, GOOGL, INTC, TUR, EWZ and SUNE. Tim's firm is long BABA, BIDU, KO, MCD, NKE, NOK and SBUX.

Brian Kelly

Brian Kelly is long BTC=, U.S. dollar, GLD, EEM, CTRL calls, GSG, HYG puts, BBRY and TLT. He is short yuan. Today, he bought EEM.

Steve Grasso

Steve Grasso is long BA, CLVS, EVGN, FB, GDX, GOOGL, IMMR, KBH, KDUS, MHY, MJNA, PFE, POT, SO, T, TMUS and TWTR. His firm is long AMZN, NE, NEM, OXY, RIG, VALE, AVP, KO, MCD and USO. His kids are long EFG, EFA, EWJ, IJR and SPY.

Guy Adami

Guy Adami is long CELG, EXAS and INTC. Guy Adami's wife, Linda Snow, works at Merck.