Headlines tied to conflict in Iran prompted substantial marketplace losses and gains in the past week.

Investors may want to brace themselves for more dramatic swings, according to JPMorgan Asset Management.

Because the market’s best days often follow the worst, investors who stay the course stand to gain the most, according to the firm’s data.

The stock sector rallied on Tuesday, the last trading day of March, inspired by hopes for an end to the Iran war. But it was not an easy month for investors.

In March, the S&P 500, Dow Jones and Nasdaq indices each fell around 5% — capping off a losing quarter. This also touches on aspects of portfolio.

Investors may want to brace themselves for more dramatic swings: The markets are poised to be “extremely sensitive to headlines, both positive and negative,” mentioned Jack Manley, global sector strategist at JPMorgan Asset Management.

“Now is still a excellent time to be taking risk, but realize it is going to be a choppy, bumpy ride over the course of this year,” Manley mentioned.

While jittery investors may be tempted to sit out the marketplace turbulence, those who move in and out of investments stand to lose the most, JPMorgan Asset Management data shows.

In the past two decades, six of the market’s 10 best days happened within two weeks of its 10 worst days, according to the firm’s analysis of S&P 500 data. The second-worst day of 2020, March 12, was immediately followed by the second-best day of the year.

Investors who stay fully invested stand to earn the best returns, JPMorgan Asset Management found. The more “best days” investors miss by moving in and out of the markets, the worse their returns, the firm’s data shows.

To better weather the volatility, it also helps to stay diversified, Manley mentioned.

U.S. equities a ‘great place to generate wealth’

A set-it-and-forget-it S&P 500 index investment strategy comprised of large-cap U.S. equities has been a winner, with three consecutive years of double-digit gains — around 16% in 2025, 23% in 2024 and 24% in 2023.

The S&P 500 is not on pace to match those gains in 2026, as it is down about 3.5% year to date.

“In any given year, you might have a negative year being a U.S. stock investor,” Manley remarked. “But over the long run, history has shown very clearly that U.S. equities are a great place to generate wealth.”

While headlines about the conflict in Iran sway the markets, other events like the U.S. intervention in Venezuela, talk of acquiring Greenland and the collapse of the Japanese bond industry were already fueling uncertainty.

“It’s not like this economy was on fire before the conflict kicked off,” Manley mentioned.

To prepare for prospective marketplace choppiness, it’s best to stay diversified, Manley commented, with exposure to international, fixed-income and other categories like real estate or real assets that are uncorrelated to economy returns.

Having a plan can also help investors stay the course when emotional or stressful unexpected events arise, commented Brian Schmehil, a certified financial planner and managing director of wealth management at The Mather Group in Chicago.

Ideally, that includes enough cash to provide for short-term goals and a “good game plan” for long-term investments, Schmehil mentioned.

By rebalancing regularly and understanding your personal risk tolerance, investors have a better chance of staying the course, rather than bailing if their portfolio balance or emotions reach uncomfortable levels.

It also helps to utilize a reputable financial advisor as a sounding board, Schmehil stated.

“Everybody thinks the wealth advisor is supposed to pick the best stocks or give you the best tax strategy,” Schmehil mentioned. “That is true, but with the age of AI, a lot of that stuff’s going to be table stakes.”

“What’s really going to matter is having somebody that can understand your emotions,” he mentioned., according to Schmehil