Airbnb Inc. and DoorDash Inc. fell on Monday after a pair of Wall Street analysts warned that first-day trading surges last week left their market valuations at precarious levels.

Airbnb’s valuation is “more than stretched” when compared with other travel peers, research firm Gordon Haskett said in a note downgrading the stock to underperform from buy.

Similarly, D.A. Davidson said DoorDash’s price leaves little room for performance “hiccups” over the next year. The firm cut its rating to neutral from buy. Both stocks fell at least 10 per cent on Monday.

Airbnb and DoorDash both soared on their first day of trading following initial public offerings last week, prompting debate about the pricing process and offering the latest sign of stock market exuberance. DoorDash jumped 86 per cent on Dec. 9, only to be topped the following day by Airbnb’s 113 per cent advance.

Airbnb was trading around 15 times 2022 revenue estimates, compared with an average of four times for online travel agency peers, Gordon Haskett analyst Robert Mollins wrote.

Analysts at firms that underwrote the IPOs won’t publish research before a quiet period expires Jan. 4. Of the five analysts tracked by Bloomberg that cover Airbnb, two have buy ratings, one a hold and two say sell. DoorDash has one buy, three hold ratings and no sells.