The "Fast Money" traders debated whether it's time to pile into the battered biotechnology sector after the iShares Nasdaq Biotechnology ETF gained 3 percent on Monday.

Trader Guy Adami said he still believes investors should hold onto the biotechnology stocks. He said Amgen's 3 percent gain on Monday backs up that investment thesis. With its "very reasonable valuation," Adami said "there's no reason not to like" Amgen, "except that the market doesn't give it the credit I think it's due."

Trader Tim Seymour said "best of breed" companies like Celgene and Biogen are proving the strength of their balance sheets.

"These companies at these valuations are very interesting and these are companies that are doing four or five or six major products across their business line. Those are companies you want to invest in," Seymour said.

Disclosures:

TIM SEYMOUR

Tim Seymour is long APC, AVP, BAC, BBRY, CLF, DO, DVYE, EDC, EWZ, F, FB, FCX, FXI, GM, GOOGL, GRMN, GE, INTC, LQD, M, MCD, MPEL, NKE, RACE, RAI, RH, RL, SINA, T, TWTR, UA, VALE, VZ, XOM and short: SPY, XRT. His firm is long ABX, BABA, BIDU, CBD, CLF, EWZ, F, HD, KO, MCD, MPEL, NKE, PEP, PF, SAVE, SBUX, SINA, VALE, VIAB, WMT, WEN, X, YHOO and short HYG, IWM, UAL.

KAREN FINERMAN

Karen Finerman is long AAL, BAC, C, DAL, DRII, DRII calls, FB, FL, GOGO, GOOG, GOOGL, JPM, LYV, KORS, KORS calls, KORS puts, M, MA, SEDG, SPY puts, UAL, URI, WIFI long call spreads. Her firm is long ANTM, AAPL, BAC, C, C calls, DRII, DRII calls, FB, GOOG, GOOGL, JPM, JPM calls, KORS, LYV, M, MOH, PLCE, SPY puts, URI, WIFI. Her firm is short IWM, MDY. Finerman is on the board of GrafTech International.

STEVE GRASSO

Steve Grasso is long BA, CC, EVGN, KBH, MJNA, MON, MU, OLN, PFE, PHM, T, TWTR, GDX. Grasso's children Own EFA, EFG, EWJ, IJR, SPY. No shorts. Stuart Frankel & Co Inc. and some of its Partners have a financial interest in DVN, LDP, WDR, AVP, CVX, FCX, ICE, KDUS, KO, MAT, MCD, MJNA, NE, NEM, OLN, OXY, RIG, STAG, TAXI, TEX, TITXF, URI, VALE, WDR, WYNN, ZNGA, CUBA, HSPO, ICE, AMZN, MJNA, TITXF, NXTD, SPY, QQQ, DIA, XLI, BGCP, VIRT, JCP, GE, AIR, FP.

GUY ADAMI

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