What happened

Shares of medical device maker ShockWave Medical (NASDAQ:SWAV) popped 29.8% in April, according to data from S&P Global Market Intelligence. The S&P 500 index returned 4.1% last month.

The company describes itself as a pioneer in the development and commercialization of Intravascular Lithotripsy (IVL) to treat complex calcified cardiovascular disease. This technology uses sonic pressure waves, hence the company's name.

ShockWave's Intravascular Lithotripsy (IVL) device, which looks like a rectangular gadget with a wand attached.

Image source: ShockWave Medical.

So what

On April 24, ShockWave stock jumped 10.2% after the company announced that it would release first-quarter 2019 results on May 8. (Yes, today.) Shares continued to rise for the next couple of trading days.

The company didn't release any other notable news at about the time its stock got a nice boost, nor does it appear to have been the subject of any market-moving news. Thus, it seems the setting of the earnings release date was the primary catalyst for ShockWave stock's strong April performance. This announcement likely led more investors to discover the stock, as the company has only been publicly traded since early March.

SWAV Chart

Data by YCharts.

Here's how ShockWave stock has performed since its initial public offering (IPO). 

SWAV Chart

Data by YCharts.

Now what

Investors don't have long to wait for material news, as ShockWave Medical is scheduled to report its first-quarter 2019 results after the market close today.

Wall Street expects the company to post a loss per share of $0.52 on revenue of $5.7 million.