What happened

Shares of Repligen (RGEN -2.20%) rose nearly 13% last month, according to data provided by S&P Global Market Intelligence. That easily bested the 12.5% drop of the S&P 500 in March. But the stock's performance probably had little to do with the coronavirus pandemic.

Investors likely remember that shares tumbled at the end of February when the company reported full-year 2019 operating results. The business delivered impressive revenue and earnings growth last year, but Repligen issued full-year 2020 guidance that disappointed Wall Street analysts. 

In other words, Mr. Market figured shares of Repligen had already been through enough and didn't require a correction alongside the rest of the stock market. Investors might want to consider that the worst is yet to come for the growth stock.

An arrow bouncing up shelves on a wall.

Image source: Getty Images.

So what

Repligen develops the consumables and single-use products required to safely and efficiently manufacture biologic drugs, including monoclonal antibodies, cell therapies, and gene therapies. Through a combination of in-house research and development and well-timed acquisitions, the business has capitalized on the remarkable growth opportunities within the biopharma sector.

While the company's diverse customer base has helped it to spread risk in recent years, it might also concentrate risk in the current environment. That's because the coronavirus pandemic has disrupted clinical trials across the pharmaceutical industry, and Repligen generated 65% of full-year 2019 revenue from clinical trials. Mr. Market doesn't seem to be taking that statistic into account.

Now what

Under normal circumstances, Repligen is a formidable growth stock thanks to the company's successful efforts to embed itself into the DNA of the biopharma sector. But these are not normal circumstances. If delays to clinical trials linger for too long, then investors can expect the business to feel the pinch. That said, the company entered 2020 with $528 million in cash, which is more than enough to endure a prolonged period of uncertainty.