Miley Cyrus Performs at Crypto Billionaire's Private Party in Hamptons

Miley Cyrus sure knows how to party in the USA ... 'cause right on the heels of killing it at Lollapalooza, she hit the Hamptons for a crypto billionaire's private rager.

The singer performed over the weekend at the home of Mike Novogratz ... CEO of Galaxy Investment Partners. Miley wore a red leotard, black heels and messy blonde hair during her set for Mike's soiree -- keep in mind, he's not just known for his business acumen, but also for being a serious party animal.

While Mike was hanging out with his guests, including Bobby Shmurda ... MC belted out some of her best hits, including "Party in the USA" and "Wrecking Ball." According to Page Six ... she also covered Sinead O'Connor's "Nothing Compares 2 U."

The private bash apparently had a Coney Island mermaid parade theme. Get this ... there was even a pop-up of Nathan's complete with a hot dog eating contest and an appearance from the 76-hot dog crushing man himself, Joey Chestnut.

There were also tents offering partygoers booze and food ... plus ice cream stands throughout, and one of those "silent disco" areas, where everyone listens on headphones.