What happened 

Shares of Wynn Resorts (WYNN 2.78%) jumped 15.5% last month, according to data provided by S&P Global Market Intelligence, as investors bet on success for the company's new Encore Boston Harbor resort. The gains didn't stop in June, either, with shares up 7.2% in the first two days of July. 

So what 

The big news for the month was the June 23 opening of Encore Boston Harbor, the $2.6 billion resort in Everett, Massachusetts. The property is Wynn's first U.S. expansion outside of Las Vegas and could open a new East Coast market for the company. Investors won't know how operations are going for a few months, but for now they're excited about the property's addition to the portfolio. 

Encore Boston Harbor with a cloudy sky.

Image source: Wynn Resorts.

It also didn't hurt that May's gambling figures from Macao showed $3.21 billion in casino revenue, which was the best month so far this year. Fears that the region could go into a protracted slowdown in 2019 have subsided, and it's back to business as usual for the world's largest gambling market. 

Now what

I would put more focus on Macao's numbers because that's still where Wynn Resorts generates most of its revenue. But as the year goes on, we will see if the bet on the Boston market is going to pay off for the company. Wynn has made a huge investment there, and it's a gamble that high-rollers will want to play while in New England, which isn't yet guaranteed for any casino operator.