Airbnb is invading these US cities

Airbnb is still small, but itsfootprint is ballooning in some major US cities.

In a note to clients, Shaun Kelley and Dany Asad at Bank of America Merrill Lynch laid out just where Airbnb is catching on in the US.

"Thematically, we do not believe Airbnb represents an existential threat to the traditional lodging industry; however, home-sharing is an important phenomenon that is not going away," said Kelley and Asad.

While Airbnb has undergone explosive growth, it still represents a small

part of the overall US lodging market with just 1-2% of US room demand and 2-4% of supply based on Kelley and Asad's estimates.

While the impact on the broad markets it still negligible. There are some certain cities, especially large ones, have been swarmed by Airbnb.

"At present, we believe Airbnb’s impact will be particularly felt in certain urban areas, among longer-stay guests and during peak leisure travel periods," said the note.

Tops among these cities is Miami with 15.3% of the market's hotel room supply, followed closely by New York and Los Angeles. The chart also breaks down percent of supply for the top 25 markets, along with the averages for the US, top 25 markets and markets outside the top 25.