Strategists at Bank of America Merrill Lynch predict that the S&P 500 Index (SPX) will end the year at 2,450, or 4% below its opening value on Monday. However, "underneath the surface, there are quite a few opportunities out there," as Marc Pouey, BofA Merrill Lynch senior equity strategist, told CNBC. In particular, he believes that financials and health care stocks are likely to maintain value even amid a general selloff, given that both sectors are trading at relative discounts to the broader market.

While Pouey did not mention any specific stocks in his remarks to CNBC, one may look at the largest by market cap as reasonable proxies for each sector. Within financials, these are: JPMorgan Chase & Co. (JPM), $349 billion; Bank of America Corp. (BAC), $284 billion; and Wells Fargo & Co. (WFC), $280 billion.

Among health care stocks, they are: Johnson & Johnson (JNJ), $365 billion; Pfizer Inc. (PFE), $218 billion; Novartis AG (NVS), $206 billion; and UnitedHealth Group Inc. (UNH), $195 billion.

Growth Story in Financials

Merrill Lynch's Pouey likes financials based on strong dividend growth, at about 10% per year, and share repurchase programs that are proceeding "very, very aggressively," as quoted by CNBC. Meanwhile, technical analysts at Strategas Research Partners are bullish on financial stocks right now.

"The relative performance of the financials sector has also re-accelerated over recent weeks and is on the cusp of making new highs," as Chris Verrone of Strategas indicates in another CNBC report.

For the year-to-date through October 6, the S&P 500 Financials Select Sector Index (IXM) is up by 13%, per S&P Dow Jones Indices. For the same period, per Investopedia data, shares of the three big banks are up by: JPMorgan Chase, 15%; Bank of America, 20%; and Wells Fargo, 3%.

Regarding valuation, Pouey tells CNBC that the S&P 500 currently trades at a forward P/E ratio of 17.8. By comparison, the forward P/Es on these three bank stocks are 12.8, 12.0, and 12.5, respectively, per Thomson Reuters data reported by Yahoo Finance.

Consistent Beats in Health Care

In nearly every quarter during the last three years, health care stocks consistently have beaten analysts' estimates for revenues and earnings, Pouey tells Barron's. Within health care, he singles out biotech as a "shining area," Barron's adds. (For more, see also: Why Biotech's Rally May Push These 8 Stocks Higher.)

For the year-to-date through October 6, the S&P 500 Health Care Select Sector Index (IXM) is up by 20%. The four big health care stocks are up by: J&J, 18%; Pfizer, 14%; Novartis, 22%; and UnitedHealth, 25%. Their respective forward P/Es are: 17.2, 13.1, 16.4, and 18.1. All these figures are per the same sources for financial stocks.