Hublot Spirit of Big Bang Moonphase King Gold 42mm 647.OX.1138.RX

The Hublot Spirit of Big Bang Moonphase 647.OX.1138.RX is one of the most visually arresting complications in Hublot's current catalog, combining the brand's iconic tonneau-shaped Spirit of Big Bang case with a poetic moonphase display and a fully open-worked movement. At 42mm, this reference occupies a versatile sweet spot within the Spirit of Big Bang family — substantial enough to command attention on the wrist yet refined enough for formal occasions. Built entirely in Hublot's exclusive King Gold — a proprietary 18-karat red-gold alloy developed in-house to resist scratching and maintain a richer, longer-lasting luster than standard 18k rose gold — the case, bezel, and visible movement architecture all share a unified warm-toned palette.

The Spirit of Big Bang line was introduced as a tonneau-shaped evolution of the round Big Bang that launched Hublot's modern era in 2005. Where the original Big Bang captured attention with its bold porthole bezel and multi-layered lug system, the Spirit of Big Bang elongates those proportions into a curved barrel shape that traces its aesthetic DNA back to Hublot's earliest barrel-cased references from the 1980s. Reference 647.OX.1138.RX represents the line's most romantic iteration, adding a moonphase complication that brings celestial poetry to a collection better known for horological bravado.

The skeleton dial of the 647.OX.1138.RX removes every gram of superfluous material, leaving only the architectural bridges, wheels, and oscillating rotor visible beneath sapphire crystal. Index hour markers punctuate the dial ring with just enough structure to keep the watch legible, while the moonphase aperture — typically displayed on the lower half of the dial — introduces a blue, star-filled disc whose lunar disc tracks the synodic cycle of the moon. The interplay between the warm King Gold movement components and the cool celestial backdrop is a deliberate and highly effective design contrast.

Powering the 647.OX.1138.RX is a Hublot automatic movement with moonphase functionality, its construction fully on display through the skeletonized architecture. The rubber strap — a Hublot hallmark since the brand's founding in 1980 and a material the brand elevated to haute horlogerie status — keeps the watch secure and comfortable in daily wear, and it pairs with the King Gold case in a manner that feels both sporting and dressy. The combination of precious metal and high-performance elastomer is, in many ways, the definitive Hublot aesthetic statement.

For collectors evaluating the 647.OX.1138.RX, this reference offers a compelling argument: a moonphase complication in a case material that appreciates in desirability, a fully skeletonized dial that rewards close inspection, and a 42mm diameter that transitions naturally from a business setting to an evening event. King Gold references in Hublot's catalog consistently attract strong secondary-market interest owing to the exclusivity of the alloy and the limited production runs associated with precious-metal Big Bang and Spirit of Big Bang variants.

Bizak & Co. offers this brand-new Hublot Spirit of Big Bang Moonphase 647.OX.1138.RX at competitive pricing with the assurance of authenticity that comes from an established luxury watch dealer. Whether you are adding a first Hublot to your collection or seeking a statement moonphase complication in precious metal, our team is ready to assist. Visit bizakandco.com or contact us directly to confirm availability, discuss pricing, and arrange secure shipping for your purchase.