Originally Published: 21 JUL 21 12:02 ET

By Paul R. La Monica, CNN Business

(CNN) -- When the market is plunging like it did last Friday and on Monday, it's tempting to throw in the towel and sell. Big drops can be scary.

But dumping stocks on days when the Dow is getting whacked is usually the wrong thing to do. Stocks roared back Tuesday and were up again Wednesday.

Yes, the Delta variant of Covid-19 has led to an alarming uptick in coronavirus cases in the United States and around the globe. But many experts think the massive number of vaccinations that have already taken place will prevent the economy and markets from going into another tailspin.

If you're investing for the long haul, the best thing you can do is ride out this wave of volatility.

"Stay invested," said Seema Shah, chief strategist at Principal Global Investors. Shah told CNN Business that the Delta variant is highly unlikely to stop the economic recovery in the US and other parts of the developed world where vaccination rates are high.

"The vaccine is effective," she said. "If cases are rising but hospitalization rates remain low, then the reopening measures from governments will continue."

Still, Shah conceded, investors should be more selective. After all, the S&P 500 has nearly doubled from its pandemic lows in March 2020, and not all stocks and sectors will maintain their momentum.

She thinks defensive sectors might start to pull back a bit. Those include utilities, health care and others companies that pay big dividends and are considered good bond proxies.

The FAANGs and other big tech stocks, many of which have strong earnings momentum and tons of cash, should continue to rally, she said.

Not the time to bail on the market

So should economic recovery plays in the travel and retail sectors that have pulled back lately on Covid concerns. United, for example, issued an upbeat outlook after the closing bell Tuesday.

"Airlines have been beaten up," Shah said. "But if you assume the reopening will continue, they should enjoy a significant bounceback."

Stocks may remain bumpy for the foreseeable future, but that shouldn't dissuade investors from sticking with their longer-term investments.

"The uncertainty of the past couple of days is warranted for the short term," said Peter van der Welle, multi-asset strategist at Robeco. "But there should be a second leg to the reflation trade."

Van der Welle noted that there are many reasons to be optimistic about continued gains in consumer spending and retail sales, despite a recent drop in consumer confidence.

Buy the dips

Any wariness on the part of consumers — and investors, for that matter — could turn out to be fleeting.

"If you are a long-term investor, take advantage of this volatility and add to positions in companies and sectors you really like," said Phil Orlando, chief equity market strategist at Federated Hermes.

He he belives stocks in cyclical industries that have gotten hit because of Delta variant fears could enjoy the biggest rebounds.

"There are stocks that have hit an air pocket that could be very attractive. We love the economically sensitive sectors," Orlando added, saying that banks and other financials, industrial firms, retailers and energy stocks may come roaring back.