Entrepreneur Anant Ambani spotted wearing a Richard Mille

At a high-profile social appearance, Anant Ambani was photographed wearing what is arguably one of the most extraordinary wristwatches in private hands today: the Richard Mille RMS10 Piece Unique Koi Fish Tourbillon, crafted in 18k yellow gold with a diamond-set dial depicting koi — a centuries-old Asian symbol of prosperity and perseverance. The sighting immediately drew attention from the global collector community.

The RMS10 designation sits within Richard Mille's bespoke and highly secretive special-commission architecture. The base caliber draws on the brand's RM10 movement lineage — an automatic tourbillon featuring a skeletonized architecture, variable geometry rotor, and a free-sprung balance with variable inertia. Case construction in 18k yellow gold is itself a departure from the brand's more prevalent titanium and carbon composite offerings, adding substantial heft and warmth to the tonneau form. The defining element, however, is the dial: an haute joaillerie construction in which koi fish motifs are assembled from individually set diamonds and polychrome precious stones, demanding hundreds of hours of lapidary and setting work from Richard Mille's artistic workshop.

From a collector standpoint, Piece Unique commissions from Richard Mille occupy a category entirely their own. They are not listed, not auctioned in the traditional sense, and not available through any retail channel. They exist because a client — typically one with an existing deep relationship with the manufacture — requests something unrepeatable. That exclusivity is absolute. No two RMS-prefixed references are alike by definition, and provenance is tied directly to the original commissioner.

Anant Ambani, an entrepreneur and philanthropist increasingly visible on the global stage, has demonstrated a serious and consistent interest in ultra-high-end horology. The Ambani family's affinity for Richard Mille is well documented within Indian collector circles, and this particular commission reflects both the financial scale and the cultural symbolism — koi representing fortune and familial strength — that would resonate deeply within that context.

With a reported value exceeding one million US dollars, the RMS10 Koi Fish Tourbillon sits beyond conventional grey-market pricing structures. Piece Unique Richard Mille commissions of comparable artistic complexity have achieved between $1.5 million and $3 million at auction when they have appeared — which is rare. This watch, should it ever surface publicly, would command serious attention from the world's top collectors.