Yahoo Finance 
Allbirds, the buzzy sneaker startup that's now reportedly worth $1 billion, just released its most expensive shoe yet
Allbirds has released its newest shoe. Called the Tree Topper, it's a high-top sneaker that retails for $US115.
The new sneaker is the first to incorporate all of the company's sustainable materials, including its new soles that are made out of a foam derived from sugar. It's also Allbirds' most expensive shoe so far.
This comes after Allbirds scored a $US50 million Series C investment that reportedly valued the company at more than $US1 billion.
Allbirds, the loveable comfy sneakers made from sustainable materials, have a new big brother.
Called the Tree Topper, it's the largest shoe Allbirds has made yet, and it has the silhouette of a classic high-top sneaker.
The new sneaker is the first to incorporate all of the company's sustainable materials, including its new "Sweetfoam" soles made out of EVA foam derived from sugar, its proprietary Merino wool blend, and a stretchy fabric made from eucalyptus tree pulp.
The new sole foam was introduced in the company's limited-run flip-flop in August, and the company estimated that it would roll out to the rest of Allbirds' line by the end of the year.
"The Tree Topper is a true representation of our approach to design and sustainability," Jamie McLellan, Allbirds' head of design, said in a prepared statement.
It's also the most expensive so far, retailing for $US115. All other Allbirds sneakers, save for the flip-flops, retail at $US95.
The new sneaker is less of a radical evolution of Allbirds' sneakers, but it does hint at the company's future of higher-priced models and doubling down on sustainability.
The new sneaker release comes about a month after the company announced a Series C round of financing to the tune of $US50 million. Tiger Global Management, T. Rowe Price Investment Management, and Fidelity Management all contributed to the round, which valued the company at about $US1 billion, according to the Wall Street Journal.
