The start to 2025 has proven challenging for investors as changes in U.S. trade policy usher in uncertainties regarding the economy. In March, the S&P 500 index faced a 5.8% decline, with weakness continuing into April, down 12.3% year to date as of this writing.

Yet, amid the stock market turbulence, winners have emerged. Let's examine the two best-performing S&P 500 stocks from last month to see if they offer opportunities for your portfolio in a volatile market.

1. Dollar General (up 18.5% in March)

Following a disappointing 2024 when Dollar General (DG -1.40%) reported a string of weaker-than-expected sales, the discount stores leader is perhaps the stock market's biggest comeback story this year.

Not only did its shares rally 18.5% in March, the stock is also up 26% year to date as of April 21. Initiatives implemented by management to restore growth and improve profitability are paying off. For 2025, the company is guiding for net sales growth between 3.4% and 4.4% alongside a rebound in earnings per share (EPS).

Dollar General stands to benefit as bargain-hunting shoppers flock to its stores during these uncertain times. With shares trading at a compelling forward price to earnings (P/E) ratio of 17, and offering a 2.5% dividend yield, Dollar General is well-positioned to continue rewarding shareholders.

2. Huntington Ingalls Industries (up 16.2% in March)

Huntington Ingalls Industries (HII 0.36%) is a major defense contractor specializing in military shipbuilding, including aircraft carriers and submarines for the U.S. Navy and Coast Guard.

Despite mixed financial trends in recent years, the company received a significant boost in March 2025 when President Donald Trump addressed a joint session of Congress, laying out a plan to revitalize U.S. shipbuilding, citing its importance to national security. The stock climbed 16.2% in March and has added to those gains since.

Huntington Ingalls Industries now expects over $50 billion in long-term contract awards over the next 24 months -- an impressive tailwind for its earnings. Given the company's unique profile and category leadership, this stock should be on more investors' radars.