For years, Macau was a gold mine for Las Vegas gaming companies.
Money made in Macau helped get gaming companies survive the recession.
And the southern Chinese gambling outpost has since been a big money winner.
But could Macau's fortunes be changing?
Wynn resorts stock fell 12 to 14 percent a few weeks ago after the company reported slowing business in October.
Howard Stutz with CDC Gaming Reports said, in October, Macau gaming revenue was $3.38 billion -- the single highest monthly figure ever for the gaming enclave.
However, it is only a few percentage points higher than the same figure in 2017.
Stutz says there are a number of reasons for the slowdown, including a slowing in the Chinese economy, the trade war between the United States and China and softness in high roller play after a crackdown on junkets a few years ago.
The slowdown is bad news for two companies in particular.
"Two companies most affected by this are Las Vegas Sands Corporation and Wynn Resorts, because anywhere between 65 – 75 percent of their quarterly revenues come from Macau," Stutz said.
MGM Resorts International also has casinos in Macau, but most of its money is being made in the U.S.
Stutz said there is no way to know for sure right now whether the decline in revenue is a harbinger of more tough times ahead.
He said there are some positive signs on the horizon that might keep Macau from sliding further, including the newly opened Hong Kong-Zhuhai-Macau bridge.
It is the world's longest sea-crossing bridge. It allows direct travel from the mainland city of Zhuhai to the islands of Macau and Hong Kong.
In addition, Macau is looking at diversifying entertainment options to attract more tourists.
"The Macau government wants to see Macau develop a lot of non-gaming [options, and] become a lot like Las Vegas," Stutz said. "They don’t want it to be completely dependent on gambling."
Stutz said Wynn Resorts is looking at creating an events center on a seven-acre piece of land it owns in Macau.
Las Vegas companies did the same thing when they started to see fewer people come to the city just to gamble. Now, 65 percent of the city's revenue is from shows, retail, restaurants and hotel rooms.
Not making that pivot after casinos starting opening in Maryland and Pennsylvania nearly killed Atlantic City, Stutz said.
Howard Stutz, executive editor, CDC Gaming Reports
