What happened 

Shares of Las Vegas Sands (LVS -3.96%) fell 18% in May, according to data provided by S&P Global Market Intelligence, as Macau's struggling gaming market hit the industry hard. It also didn't help that the market fell overall, and gaming stocks usually take market drops harder than the average stock. 

So what 

The biggest driver of Las Vegas Sands' drop was an 8.3% decline in Macau's reported gaming revenue versus a year earlier. The company generates 59% of its EBITDA, a proxy for cash flow, from Macau, and any decline there will hit the company hard. 

Macau Peninsula's skyline from Cotai.

The Macau skyline. Image source: Getty Images.

There was also worry that an extended trade war with China or Mexico will lead to a recession in the U.S., which could result in a decline in gaming and related spending. If China's economy also struggled, it would be a double whammy for Las Vegas Sands. 

Now what 

Macau's gaming revenue will rise and fall month to month depending on the economy, holidays, and even how lucky large gamblers are over a few days. So I wouldn't read too much into a down month for Macau. In May, gaming revenue was up 1.8% compared with a year ago, and so far in 2019 gaming revenue is only down 1.6%. Until we see more signs that a contraction is protracted, Las Vegas Sands is one of the top gaming stocks to own long term.