Cartier Ballon Bleu: The Best-Selling Cartier You Should Be Buying Pre-Owned

The Ballon Bleu is the watch that collectors love to dismiss and civilians love to buy, and there's a lesson in that gap. When it launched in 2007, serious watch people called it 'too round,' 'too safe,' and 'too feminine for men.' Meanwhile, it became the best-selling Cartier watch ever made. The real collector play with the Ballon Bleu isn't the standard steel models: it's the early-production complications. The Ballon Bleu Flying Tourbillon (ref. W6920045) and the Ballon Bleu Extra-Flat have genuine scarcity and horological interest. A tourbillon Ballon Bleu that listed at $100,000+ retails can sometimes surface for $50,000-$70,000 pre-owned: which, for a Cartier tourbillon, is remarkable. The other piece of lore: the 42mm Ballon Bleu was originally marketed as a men's watch when big watches were trendy. Now, in 2025, the trend has reversed: 36mm is the 'right' size. Result: 42mm models trade at even steeper discounts, making them hidden bargains for men who like a traditional-size watch. Give it five years; when the trend pendulum swings back, those 42mm pieces will look like a steal.