The S&P 500 can generate massive wealth. But stocks can decimate portfolio values, too.

Morningstar says just 15 stocks, including Biogen (BIIB), Walgreens Boots Alliance (WBA) and Intel (INTC), collectively destroyed $371 billion in shareholder wealth in the past 10 years.

"Shareholders in these 15 companies have suffered greatly over the past 10 years," said Amy Arnott, author of the report.

Looking At The Damage

Biogen, a developer of autoimmune disease treatments, is the largest disappointment. The stock shredded more than $69 billion in shareholder wealth in the past decade. That's worse than any other stock on Morningstar's list.

The company just can't seem to find its hit product. Analysts think its profit per share will fall 3% in 2025 and 1% in 2026. Meanwhile, it sports a near rock-bottom RS Rating of 13 of a best-possible 99. Morningstar says the business has a small "moat," meaning it's not protected from competition. It has backed away from an Alzheimer's treatment that would have helped make up for other products' falling revenue.

Some of the big stock disappointments are due to a once-dominant firm faltering. Struggling chipmaker Intel is an example. The company used to dominate computer semiconductors, but it's slipping behind. The stock wiped out $21.7 billion in wealth in the past 10 years. Intel shares have an RS Rating of just 23. Analysts think its profit will rebound in 2025. But it only has an EPS Rating of 6.

Putting Losses Into Perspective

Don't let the size of these losses scare you from investing in stocks, though. They're actually just a sliver of the $20.8 trillion investors made on the top 15 wealth-generating S&P 500 stocks in the past 10 years.

It's a reminder investors need to keep an eye out for wealth-destroying events and use proper selling rules. Events for investors to look out for, Morningstar says, include botched mergers, slipping behind in consumer trends, difficult macroeconomic events and a weak pipeline of new products.

"What really matters for investors considering a new purchase is a company's future prospects and whether the current stock price offers a margin of safety," Morningstar's Arnott said.

Biggest Wealth Destroyers

From 2015 to 2024

Sources: Morningstar, S&P Global Market Intelligence, IBD

Follow Matt Krantz on X (Twitter) @mattkrantz

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