Stocks have done well in 2020, surprising just about everyone given the massive problems that the world has faced. The seemingly boundless optimism continued on Wednesday, as market benchmarks climbed even further to add to big gains this year. As of 1 p.m. EST, the Dow Jones Industrial Average (DJINDICES:^DJI) was up 140 points to 30,476. The S&P 500 (SNPINDEX:^GSPC) had gained 10 points to 3,737, while the Nasdaq Composite (NASDAQINDEX:^IXIC) was higher by 35 points to 12,885.

Among today's strongest gainers were two stocks that have done surprisingly well in 2020, doubling investors' money. Freeport-McMoRan (NYSE:FCX) hasn't been high on the list of much-followed stocks this year, but it should've been, as the copper miner's share price has soared lately. Meanwhile, insurance provider Lemonade (NYSE:LMND) has been a big IPO in 2020, and it's recovering from a brief setback earlier this week.

Two hands pushing piles of poker chips forward.

Image source: Getty Images.

Freeport shines again

Shares of Freeport-McMoRan were up another 7% on Wednesday afternoon. That brought the stock's gains for 2020 to 102%, and the copper and gold mining company is serving as a bellwether for investor sentiment about the broader U.S. economy.

Many economists have looked at copper prices as a gauge of industrial activity. The metal is used in all sorts of applications, ranging from piping in residential and commercial construction to components in the technology industry.

Most recently, investors have gotten excited about copper because of its role in the move toward renewable energy and electric vehicles. The metal plays a vital role in electrical wiring, and its combination of relatively low cost and conductivity makes it a natural fit for greater use as the world transitions away from fossil fuels toward greater use of electricity.

Freeport lost money in 2019 and is on pace to post more red ink in 2020. However, its fundamental business looks poised for a turnaround, and that's why stock investors are getting an early jump on the action.

Making Lemonade

Elsewhere, shares of Lemonade picked up almost 7%. The mobile-friendly insurance provider has seen its stock make some big moves this week, but today's move higher is a vote of confidence that longtime shareholders are sticking with the company.

Lemonade went public at $29 per share back in July, and after opening trading at $50, the stock has gone on to more than double even from that higher level. Investors like the idea of Lemonade's disruptive business model, which involves heavy use of reinsurance contracts and an innovative charitable program that aligns incentives between policyholders and the insurer.

Shares plunged on Monday, however, as investors worried about the expiration of post-IPO lockup provisions. Some feared that institutional shareholders would head to the exits quickly, sending the price of the stock down sharply.

However, the lockup expiration day has come and gone, and although stock volume has risen somewhat, trading has been orderly. That's making shareholders focus more on business fundamentals, and people generally like what they see from Lemonade.

Can these stocks double again?

Both Freeport and Lemonade have a lot of potential ahead of them. Stocks can't double every year, but these two companies have a better chance than most of putting up strong back-to-back performances.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.