At America's first Rolliefest, the rules are clear: Don't reveal the location of the event on social media until it's over.
Last month, 110 watch collectors from 13 countries filed past armed guards at the Lotte New York Palace hotel in midtown Manhattan. There, some of the world's most prominent watch collectors were gathered in a gilded ballroom to admire tens of millions of dollars of vintage Rolexes.
During the weekend celebration, collectors shared their passion for the Swiss watchmaker.
A ticket to this invitation-only event cost $850 and gave collectors access to a handful of exclusive events over two days, including a private dinner and cocktail parties.
The main event was a luncheon for Rolex lovers. CNBC watched as the ballroom quickly filled with collectors who brought their favorite timepieces to share with the group.
Just about every guest is drawn to the 18-foot-long table at the center of the room, where many of the collectors pulled timepieces from cases and piled them haphazardly onto the table until it was covered in hundreds of rare wristwatches.
For more than an hour, the table was a Rolex feeding-frenzy with guests walking around the table admiring, examining and trying on the vintage watches.
One collector described it as "an orgy of Rolexes worth millions," but most of the guests in the room referred to the impressive horological display by its nickname: the "sexpile."
Many of the collectors said this mass sharing of a pile of watches is a common component of their get-togethers and so is posting photos of it to Instagram with the hashtag #sexpile.
While it may seem like an NSFW search term, when you plug the hashtag into Instagram, it delivers thousands of photos of watch "sexpiles" from around the world.
Every watch aficionado in the room was invited to America's first Rolliefest by Geoff Hess, who's also a vintage Rolex collector and consultant for Phillips auction house.
How much does Hess love Rolexes? He had his wedding band designed to mimic the links in his Rolex bracelet.
"It's a bit of a Rolex brotherhood," said Hess.
He said it's difficult to say how many watches each collector brought to the event.
"I would estimate there's at least 500 Rolex watches here today," Hess said. "Mostly from the 1950s and '60s, and perhaps some from the '70s as well."
Among the guests was Paul Boutros, head of the Americas watch department at Phillips auction house.
Boutros, a Rolex collector himself, said "I would conservatively estimate about $50 million to $100 million in vintage watches, predominantly Rolex."
Around the room, it is easy to discover some of the rare vintage finds.
There is a 1958 Rolex GMT-Master Ref. 6542 that's actually radioactive.
Rolex owner Mike Bindra said that watches in the '50s were made with the radioactive element radium to give the glow-in-the-dark effect on the bezel and face.
In his watch toolkit, Bindra carries a Geiger counter. As he placed the device over the 18-karat gold watch, it immediately detected radioactive emissions, and spikes to 99.9 microsieverts. It's the maximum reading the tiny machine can handle.
"This is as high as it goes. Can't go any higher. That thing's pretty radioactive," Bindra said. "I don't wear it for long periods of time."
For comparison, according to Harvard Medical School, a single chest X-ray exposes a person to about 0.1 mSv.
There's also a rare solid-gold Rolex made for the sultan of Oman. It belongs to Alan Hammer, a retired entrepreneur and businessman, who traveled from Australia with some of his favorite old Rolexes.
Hammer said he estimates the six pieces he chose to showcase at Rolliefest, including a gold Daytona from the '80s, and two military-issued Submariners on their original nylon straps, are valued at more than $1 million.
Other Rolex collectors like John Field, a physician from Texas, are drawn to vintage Rolexes with unusual colorings.
Two of Field's favorite pieces are both 1962 Rolex Submariners. Both were originally issued with standard black dials and bezels. But over the decades, one of the two has dramatically changed in color. Its bezel is now a faded gray and the face has turned a warm brownish hue.
It's not clear what creates the unusual patina, but some collectors, like Field, seek out watches with these distinct color variations. That's led to an increase in demand that makes a watch with a unique patina often rise in value faster than one without.
Field said the patina on his Rolex Submariner Ref. 5513 is one of the main reasons the value of his watch has increased into the six-figures.
And while most of the pieces displayed and admired at Rolliefest are super expensive, many collectors downplay their value and said the event is not about showing off or talking money.
"This is really, purely an expression of passion and love," said Hess. "It's just guys with their toys."