A six-bedroom penthouse at 450 Alton Road in Miami Beach changed hands for $23.5 million on the week of July 24, 2026, claiming the top spot among South Florida residential transactions for that period.

What sold and for how much at 450 Alton Road?

The unit is a 9,000-square-foot penthouse spanning six bedrooms and seven-and-a-half bathrooms, which traded at approximately $2,600 per square foot — a price point that placed it above every other residential deal recorded in South Florida during the week of July 24, 2026. The sale represented a notable discount from the property's most recent asking price of $28.9 million.

  • Size: 9,000 square feet with six bedrooms and seven-and-a-half bathrooms
  • Sale price: $23.5 million, or roughly $2,600 per square foot
  • Most recent list price: $28.9 million, meaning the unit sold approximately $5.4 million below asking

Who bought and who sold the Miami Beach penthouse?

Akron Warwick Exchange LLC purchased the penthouse from a trust linked to Yves Mongeau and Sylvie Guilbault, the Canadian couple who had held the property since 2013. Mongeau and Guilbault originally acquired the unit for $15 million in 2013, meaning the sale delivered a gross gain of $8.5 million over roughly thirteen years of ownership.

  • Seller: a trust associated with Yves Mongeau and Sylvie Guilbault, prior owners since 2013
  • Buyer: Akron Warwick Exchange LLC
  • Original purchase price: $15 million in 2013
  • Gross appreciation: $8.5 million between the 2013 acquisition and the July 2026 closing

What does this sale signal for Miami Beach's luxury market?

The transaction confirms that demand for large-format, ultra-luxury product in Miami Beach remains active heading into the second half of 2026, even as sellers are absorbing meaningful discounts from ambitious list prices. A closing figure of $23.5 million still ranks at the very top of the weekly South Florida leaderboard, underscoring that buyer interest in premium square footage on the island has not evaporated despite broader questions about affordability and inventory levels in the broader Miami-Dade County market.

  • 450 Alton Road sits along the western edge of Miami Beach, near Biscayne Bay
  • The $2,600-per-square-foot figure reflects strong but not record-setting per-foot pricing for Miami Beach penthouses
  • The roughly 19-percent discount from the $28.9 million ask suggests price discovery is still active in this segment

Original reporting on this transaction was published July 27, 2026, by The Real Deal Miami.