Critics roasted LVMH for spending big on Tiffany. 4 years later, the bet doesn't look so bad.

• LVMH's $15.8 billion Tiffany acquisition was its biggest ever — and was met with high expectations.
• Some investors are skeptical about the turnaround, but things are looking up at the jewelry brand.
• LVMH's playbook of marketing, price hikes, and store re-dos are setting Tiffany up to shine again.

On an April night last year, a veritable who's who — Blake Lively! Gabrielle Union! Hailey Beiber! Katy Perry in concert with the Rockettes! — made their way to midtown Manhattan. Many wore outfits with pops of robin egg blue.